Fix build errors

BUILD.gn

@@ -1087,6 +1087,7 @@ config("grpc_config") {
         "include/grpcpp/security/auth_metadata_processor.h",
         "include/grpcpp/security/auth_metadata_processor_impl.h",
         "include/grpcpp/security/credentials.h",
+        "include/grpcpp/security/credentials_impl.h",
         "include/grpcpp/security/server_credentials.h",
         "include/grpcpp/security/server_credentials_impl.h",
         "include/grpcpp/server.h",

CMakeLists.txt

@@ -3039,6 +3039,7 @@ foreach(_hdr
   include/grpcpp/security/auth_metadata_processor.h
   include/grpcpp/security/auth_metadata_processor_impl.h
   include/grpcpp/security/credentials.h
+  include/grpcpp/security/credentials_impl.h
   include/grpcpp/security/server_credentials.h
   include/grpcpp/security/server_credentials_impl.h
   include/grpcpp/server.h
@@ -3646,6 +3647,7 @@ foreach(_hdr
   include/grpcpp/security/auth_metadata_processor.h
   include/grpcpp/security/auth_metadata_processor_impl.h
   include/grpcpp/security/credentials.h
+  include/grpcpp/security/credentials_impl.h
   include/grpcpp/security/server_credentials.h
   include/grpcpp/security/server_credentials_impl.h
   include/grpcpp/server.h
@@ -4630,6 +4632,7 @@ foreach(_hdr
   include/grpcpp/security/auth_metadata_processor.h
   include/grpcpp/security/auth_metadata_processor_impl.h
   include/grpcpp/security/credentials.h
+  include/grpcpp/security/credentials_impl.h
   include/grpcpp/security/server_credentials.h
   include/grpcpp/security/server_credentials_impl.h
   include/grpcpp/server.h

Makefile

@@ -5379,6 +5379,7 @@ PUBLIC_HEADERS_CXX += \
     include/grpcpp/security/auth_metadata_processor.h \
     include/grpcpp/security/auth_metadata_processor_impl.h \
     include/grpcpp/security/credentials.h \
+    include/grpcpp/security/credentials_impl.h \
     include/grpcpp/security/server_credentials.h \
     include/grpcpp/security/server_credentials_impl.h \
     include/grpcpp/server.h \
@@ -5994,6 +5995,7 @@ PUBLIC_HEADERS_CXX += \
     include/grpcpp/security/auth_metadata_processor.h \
     include/grpcpp/security/auth_metadata_processor_impl.h \
     include/grpcpp/security/credentials.h \
+    include/grpcpp/security/credentials_impl.h \
     include/grpcpp/security/server_credentials.h \
     include/grpcpp/security/server_credentials_impl.h \
     include/grpcpp/server.h \
@@ -6927,6 +6929,7 @@ PUBLIC_HEADERS_CXX += \
     include/grpcpp/security/auth_metadata_processor.h \
     include/grpcpp/security/auth_metadata_processor_impl.h \
     include/grpcpp/security/credentials.h \
+    include/grpcpp/security/credentials_impl.h \
     include/grpcpp/security/server_credentials.h \
     include/grpcpp/security/server_credentials_impl.h \
     include/grpcpp/server.h \

build.yaml

@@ -1381,6 +1381,7 @@ filegroups:
   - include/grpcpp/security/auth_metadata_processor.h
   - include/grpcpp/security/auth_metadata_processor_impl.h
   - include/grpcpp/security/credentials.h
+  - include/grpcpp/security/credentials_impl.h
   - include/grpcpp/security/server_credentials.h
   - include/grpcpp/security/server_credentials_impl.h
   - include/grpcpp/server.h

gRPC-C++.podspec

@@ -116,6 +116,7 @@ Pod::Spec.new do |s|
                       'include/grpcpp/security/auth_metadata_processor.h',
                       'include/grpcpp/security/auth_metadata_processor_impl.h',
                       'include/grpcpp/security/credentials.h',
+                      'include/grpcpp/security/credentials_impl.h',
                       'include/grpcpp/security/server_credentials.h',
                       'include/grpcpp/security/server_credentials_impl.h',
                       'include/grpcpp/server.h',

tools/doxygen/Doxyfile.c++

@@ -1008,6 +1008,7 @@ include/grpcpp/security/auth_context.h \
 include/grpcpp/security/auth_metadata_processor.h \
 include/grpcpp/security/auth_metadata_processor_impl.h \
 include/grpcpp/security/credentials.h \
+include/grpcpp/security/credentials_impl.h \
 include/grpcpp/security/server_credentials.h \
 include/grpcpp/security/server_credentials_impl.h \
 include/grpcpp/server.h \

tools/doxygen/Doxyfile.c++.internal

@@ -1010,6 +1010,7 @@ include/grpcpp/security/auth_context.h \
 include/grpcpp/security/auth_metadata_processor.h \
 include/grpcpp/security/auth_metadata_processor_impl.h \
 include/grpcpp/security/credentials.h \
+include/grpcpp/security/credentials_impl.h \
 include/grpcpp/security/server_credentials.h \
 include/grpcpp/security/server_credentials_impl.h \
 include/grpcpp/server.h \

tools/run_tests/generated/sources_and_headers.json

@@ -10186,6 +10186,7 @@
       "include/grpcpp/security/auth_metadata_processor.h", 
       "include/grpcpp/security/auth_metadata_processor_impl.h", 
       "include/grpcpp/security/credentials.h", 
+      "include/grpcpp/security/credentials_impl.h", 
       "include/grpcpp/security/server_credentials.h", 
       "include/grpcpp/security/server_credentials_impl.h", 
       "include/grpcpp/server.h", 
@@ -10308,6 +10309,7 @@
       "include/grpcpp/security/auth_metadata_processor.h", 
       "include/grpcpp/security/auth_metadata_processor_impl.h", 
       "include/grpcpp/security/credentials.h", 
+      "include/grpcpp/security/credentials_impl.h", 
       "include/grpcpp/security/server_credentials.h", 
       "include/grpcpp/security/server_credentials_impl.h", 
       "include/grpcpp/server.h",