Bazel: Remove --spawn_strategy and --strategy options for RBE

In Bazel@HEAD this warning is issued when building on RBE:

WARNING: Use of implicit local fallback will go away soon, please
set a fallback strategy instead. See --legacy_local_fallback option.

Since release 0.27 Bazel auto detects the execution strategy, if no
strategy flag is provided. If none of the strategy flags was used,
Bazel will generate a default list of strategies (in this order):

   remote,worker,sandboxed,local

and, for every action it wants to execute, will pick up the first
strategy that can execute it.

See this blog entry for more details: [1].

[1] https://blog.bazel.build/2019/06/19/list-strategy.html

Change-Id: I6a700515fd861b947d57f003d6d1a19693dc37ed
diff --git a/tools/remote-bazelrc b/tools/remote-bazelrc
index de7d0df..22ee330 100644
--- a/tools/remote-bazelrc
+++ b/tools/remote-bazelrc
@@ -42,9 +42,6 @@
 # Set various strategies so that all actions execute remotely. Mixing remote
 # and local execution will lead to errors unless the toolchain and remote
 # machine exactly match the host machine.
-build:remote --spawn_strategy=remote,sandboxed
-build:remote --strategy=Javac=remote
-build:remote --strategy=Genrule=remote
 build:remote --define=EXECUTOR=remote
 
 # Enable the remote cache so action results can be shared across machines,
@@ -68,6 +65,3 @@
 build:remote-cache --tls_enabled=true
 build:remote-cache --remote_timeout=3600
 build:remote-cache --auth_enabled=true
-build:remote-cache --spawn_strategy=standalone
-build:remote-cache --strategy=Javac=standalone
-build:remote-cache --strategy=Genrule=standalone