ANDROID: Fix platforms config_setting values.

The values must be wrapped in a str(package_relative_label()), otherwise
they are not resolved to the correct label especially when @kleaf is not
the root module.

Bug: 377799294
Bug: 378433555
Signed-off-by: HONG Yifan <elsk@google.com>
(cherry picked from https://android-review.googlesource.com/q/commit:5c5911ff0ad7522dad1b446eef05090d14ae7ef8)
Merged-In: I100929bace62a3268af197d6fab462c89cf5fe5f
Change-Id: I100929bace62a3268af197d6fab462c89cf5fe5f