Bazel: Fix building from non-root workspace directory

Support for Remote Bazel Execution was added in this change:
Ia18e5fd55f8. However, the import statement in .bazelrc:

  import tools/remote-bazelrc

missed to prefix the tools directory with %workspace% prefix and
thus broke running the build from non root-workspace directory.

Change-Id: I85673659138e23d25eaecf40606d57706fe9f6e1
diff --git a/.bazelrc b/.bazelrc
index 433a190..fef1fa3 100644
--- a/.bazelrc
+++ b/.bazelrc
@@ -14,4 +14,4 @@
 test --build_tests_only
 test --test_output=errors
 
-import tools/remote-bazelrc
+import %workspace%/tools/remote-bazelrc