Android NDK example is not building on Windows

[jin]

See https://buildkite.com/bazel/bazel-bazel-examples/builds/8#2bad9c2a-6d02-452e-a068-2aaafd62bac7

ERROR: D:/b/bk-windows-java8-sd54/bazel/bazel-bazel-examples/android/ndk/app/src/main/BUILD.bazel:16:1: Couldn't build file app/src/main/_objs/jni_lib/native-lib.o: undeclared inclusion(s) in rule '//app/src/main:jni_lib':
--
  | this rule is missing dependency declarations for the following files included by 'app/src/main/cpp/native-lib.cpp':
  | 'D:/b/4siup6ez/execroot/__main__/external/androidndk/ndk/toolchains/llvm/prebuilt/windows-x86_64/lib64/clang/5.0.300080/include/stdarg.h'
  | 'D:/b/4siup6ez/execroot/__main__/external/androidndk/ndk/toolchains/llvm/prebuilt/windows-x86_64/lib64/clang/5.0.300080/include/stddef.h'
  | 'D:/b/4siup6ez/execroot/__main__/external/androidndk/ndk/toolchains/llvm/prebuilt/windows-x86_64/lib64/clang/5.0.300080/include/float.h'
  | Target //app/src/main:app failed to build

[laszlocsomor]

/cc @laszlocsomor

[jin]

I believe this is a remote cache issue. I ran into the same missing dependency declarations issue with rules_jvm_external's Windows examples builds.

bazelbuild/rules_jvm_external#113