Restrict mixed build cquery to deps of depth 2.

This will be the list of targets directly being requested + additional
targets necessary for mixed_root. This reduces the size of the cquery
file by ~300Kb. Additionally, it removes unnecessary targets, making it
ever so slightly easier to find what one is looking for in cquery.out
for debugging purposes.

Test: build/bazel/ci/mixed_droid.sh
Change-Id: I6d0e337c9ab7c13388459dee16415be0ab3c0506

android/bazel_handler.go

@@ -696,7 +696,7 @@ func (context *bazelContext) InvokeBazel() error {
 	cqueryOutput, cqueryErr, err = context.issueBazelCommand(
 		context.paths,
 		bazel.CqueryBuildRootRunName,
-		bazelCommand{"cquery", fmt.Sprintf("deps(%s)", buildrootLabel)},
+		bazelCommand{"cquery", fmt.Sprintf("deps(%s, 2)", buildrootLabel)},
 		"--output=starlark",
 		"--starlark:file="+absolutePath(cqueryFileRelpath))
 	err = ioutil.WriteFile(filepath.Join(soongInjectionPath, "cquery.out"),

android/bazel_handler_test.go

@@ -11,7 +11,7 @@ func TestRequestResultsAfterInvokeBazel(t *testing.T) {
 	label := "//foo:bar"
 	arch := Arm64
 	bazelContext, _ := testBazelContext(t, map[bazelCommand]string{
-		bazelCommand{command: "cquery", expression: "deps(@soong_injection//mixed_builds:buildroot)"}: `//foo:bar|arm64>>out/foo/bar.txt`,
+		bazelCommand{command: "cquery", expression: "deps(@soong_injection//mixed_builds:buildroot, 2)"}: `//foo:bar|arm64>>out/foo/bar.txt`,
 	})
 	g, ok := bazelContext.GetOutputFiles(label, arch)
 	if ok {