Fixup #12492: Address gemini assist comments about runtime exception leak

Author: sauravzg

xds/src/main/java/io/grpc/xds/GrpcServiceConfigParser.java

@@ -218,14 +218,14 @@ private static Optional<ConfiguredChannelCredentials> channelCredsFromProto(Any
               XdsChannelCredentials.create(fallbackCreds.get().channelCredentials()),
               new ProtoChannelCredsConfig(typeUrl, cred)));
         case LOCAL_CREDENTIALS_TYPE_URL:
-          throw new UnsupportedOperationException(
+          throw new GrpcServiceParseException(
               "LocalCredentials are not supported in grpc-java. "
                   + "See https://github.com/grpc/grpc-java/issues/8928");
         case TLS_CREDENTIALS_TYPE_URL:
           // For this PR, we establish this structural skeleton,
-          // but throw an UnsupportedOperationException until the exact stream conversions are
+          // but throw an GrpcServiceParseException until the exact stream conversions are
           // merged.
-          throw new UnsupportedOperationException(
+          throw new GrpcServiceParseException(
               "TlsCredentials input stream construction pending.");
         default:
           return Optional.empty();

xds/src/test/java/io/grpc/xds/GrpcServiceConfigParserTest.java

@@ -241,7 +241,7 @@ public void parse_localCredentials() throws GrpcServiceParseException {
         .addChannelCredentialsPlugin(localCreds).addCallCredentialsPlugin(accessTokenCreds).build();
     GrpcService grpcService = GrpcService.newBuilder().setGoogleGrpc(googleGrpc).build();
 
-    UnsupportedOperationException exception = assertThrows(UnsupportedOperationException.class,
+    GrpcServiceParseException exception = assertThrows(GrpcServiceParseException.class,
             () -> parse(grpcService,
                     dummyBootstrapInfo(),
             dummyServerInfo()));
@@ -285,7 +285,7 @@ public void parse_tlsCredentials_notSupported() {
         .addChannelCredentialsPlugin(tlsCreds).addCallCredentialsPlugin(accessTokenCreds).build();
     GrpcService grpcService = GrpcService.newBuilder().setGoogleGrpc(googleGrpc).build();
 
-    UnsupportedOperationException exception = assertThrows(UnsupportedOperationException.class,
+    GrpcServiceParseException exception = assertThrows(GrpcServiceParseException.class,
             () -> parse(grpcService,
                     dummyBootstrapInfo(),
             dummyServerInfo()));