Fixing some deprecation warnings

google-cloud-clients/google-cloud-bigtable/src/main/java/com/google/cloud/bigtable/data/v2/stub/mutaterows/MutateRowsAttemptCallable.java

@@ -185,7 +185,8 @@ public Void call() {
 
       // Handle RPC level errors by wrapping them in a MutateRowsException
       ApiFuture<List<MutateRowsResponse>> catching =
-          ApiFutures.catching(innerFuture, Throwable.class, attemptFailedCallback);
+          ApiFutures.catching(
+              innerFuture, Throwable.class, attemptFailedCallback, MoreExecutors.directExecutor());
 
       // Inspect the results and either propagate the success, or prepare to retry the failed
       // mutations

google-cloud-clients/google-cloud-bigtable/src/test/java/com/google/cloud/bigtable/data/v2/it/env/Emulator.java

@@ -172,10 +172,8 @@ private void waitForPort(int port) throws InterruptedException, TimeoutException
   }
 
   private ManagedChannel createChannel(int port) {
-    // NOTE: usePlaintext is currently @ExperimentalAPI. In grpc 1.11 it be became parameterless.
-    // In 1.12 it should be stable. See https://github.com/grpc/grpc-java/issues/1772 for discussion
     return ManagedChannelBuilder.forAddress("localhost", port)
-        .usePlaintext(true)
+        .usePlaintext()
         .maxInboundMessageSize(256 * 1024 * 1024)
         .build();
   }

google-cloud-clients/google-cloud-core/src/main/java/com/google/cloud/ServiceOptions.java

@@ -349,7 +349,8 @@ private static String getActiveGoogleCloudConfig(File configDir) {
     String activeGoogleCloudConfig = null;
     try {
       activeGoogleCloudConfig =
-          Files.readFirstLine(new File(configDir, "active_config"), Charset.defaultCharset());
+          Files.asCharSource(new File(configDir, "active_config"), Charset.defaultCharset())
+              .readFirstLine();
     } catch (IOException ex) {
       // ignore
     }