fix(spanner): preserve grpc metrics overload compatibility

Author: rahul2393

java-spanner/google-cloud-spanner/clirr-ignored-differences.xml

@@ -1139,9 +1139,4 @@
     <className>com/google/cloud/spanner/XGoogSpannerRequestId</className>
     <field>REQUEST_ID</field>
   </difference>
-  <difference>
-    <differenceType>7004</differenceType>
-    <className>com/google/cloud/spanner/SpannerOptions</className>
-    <method>void enablegRPCMetrics(com.google.api.gax.grpc.InstantiatingGrpcChannelProvider$Builder)</method>
-  </difference>
 </differences>

java-spanner/google-cloud-spanner/src/main/java/com/google/cloud/spanner/SpannerOptions.java

@@ -2698,13 +2698,27 @@ public OpenTelemetry getBuiltInOpenTelemetry() {
         this.getProjectId(), getCredentials(), this.monitoringHost, getUniverseDomain());
   }
 
+  /**
+   * Wires gRPC-layer built-in metrics into the given channel provider builder using the
+   * pre-emulator-aware behavior.
+   *
+   * @deprecated for internal callers only. Use {@link #enablegRPCMetrics(
+   *     InstantiatingGrpcChannelProvider.Builder, boolean)}.
+   */
+  @Deprecated
+  @InternalApi
+  public void enablegRPCMetrics(InstantiatingGrpcChannelProvider.Builder channelProviderBuilder) {
+    enablegRPCMetrics(channelProviderBuilder, /* isEmulatorEnabled= */ false);
+  }
+
   /**
    * Wires gRPC-layer built-in metrics into the given channel provider builder for each active
    * metrics sink: the Cloud Monitoring (GCM) sink when {@link #isEnableBuiltInMetrics()} is true,
    * and the caller-owned OpenTelemetry sink when a {@link CustomOpenTelemetryMetricsProvider} is
    * configured. Does nothing when {@code isEmulatorEnabled} is true or gRPC built-in metrics are
    * disabled via the environment.
    */
+  @InternalApi
   public void enablegRPCMetrics(
       InstantiatingGrpcChannelProvider.Builder channelProviderBuilder, boolean isEmulatorEnabled) {
     if (isEmulatorEnabled || !SpannerOptions.environment.isEnableGRPCBuiltInMetrics()) {

java-spanner/google-cloud-spanner/src/test/java/com/google/cloud/spanner/SpannerOptionsTest.java

@@ -31,6 +31,7 @@
 import static org.mockito.Mockito.mock;
 
 import com.google.api.gax.grpc.GrpcCallContext;
+import com.google.api.gax.grpc.InstantiatingGrpcChannelProvider;
 import com.google.api.gax.retrying.RetrySettings;
 import com.google.api.gax.rpc.ApiCallContext;
 import com.google.api.gax.rpc.ServerStreamingCallSettings;
@@ -1451,6 +1452,13 @@ public void testOmniEnforcedInConstructor() {
         Duration.ofSeconds(42), options.getSessionPoolOptions().getAcquireSessionTimeout());
   }
 
+  @Test
+  public void enableGrpcMetricsKeepsOneArgOverloadForCompatibility() throws Exception {
+    assertNotNull(
+        SpannerOptions.class.getMethod(
+            "enablegRPCMetrics", InstantiatingGrpcChannelProvider.Builder.class));
+  }
+
   @Test
   public void testCustomProviderKeepsCloudMonitoringSinkOnNonOmni() {
     SpannerOptions.useEnvironment(new SpannerOptions.SpannerEnvironment() {});