differentiate C# android artifacts by ABI

tools/run_tests/artifacts/artifact_targets.py

@@ -212,11 +212,15 @@ class RubyArtifact:
 class CSharpExtArtifact:
     """Builds C# native extension library"""
 
-    def __init__(self, platform, arch):
+    def __init__(self, platform, arch, arch_abi=None):
         self.name = 'csharp_ext_%s_%s' % (platform, arch)
         self.platform = platform
         self.arch = arch
+        self.arch_abi = arch_abi
         self.labels = ['artifact', 'csharp', platform, arch]
+        if arch_abi:
+          self.name += '_%s' % arch_abi
+          self.labels.append(arch_abi)
 
     def pre_build_jobspecs(self):
         return []
@@ -227,7 +231,7 @@ class CSharpExtArtifact:
                 self.name,
                 'tools/dockerfile/grpc_artifact_android_ndk',
                 'tools/run_tests/artifacts/build_artifact_csharp_android.sh',
-                environ={})
+                environ={'ANDROID_ABI': self.arch_abi})
         elif self.platform == 'windows':
             cmake_arch_option = 'Win32' if self.arch == 'x86' else self.arch
             return create_jobspec(
@@ -348,7 +352,8 @@ def targets():
         for Cls in (CSharpExtArtifact, ProtocArtifact)
         for platform in ('linux', 'macos', 'windows') for arch in ('x86', 'x64')
     ] + [
-        CSharpExtArtifact('linux', 'android'),
+        CSharpExtArtifact('linux', 'android', arch_abi='arm64-v8a'),
+        CSharpExtArtifact('linux', 'android', arch_abi='armeabi-v7a'),
         PythonArtifact('linux', 'x86', 'cp27-cp27m'),
         PythonArtifact('linux', 'x86', 'cp27-cp27mu'),
         PythonArtifact('linux', 'x86', 'cp34-cp34m'),

tools/run_tests/artifacts/build_artifact_csharp_android.sh

@@ -17,7 +17,7 @@ set -ex
 
 cd "$(dirname "$0")/../../.."
 
-export ANDROID_ABI=armeabi-v7a
+# ANDROID_ABI is set by the job definition in artifact_targets.py
 src/csharp/experimental/build_native_ext_for_android.sh
 
 mkdir -p "${ARTIFACTS_OUT}"