[Panlingual] Dynamic locales

Allows applications to  update their list of supported locales while running, without an update of the app’s software.

Bug: 248446474
Test: atest LocaleManagerTests
      atest LocaleConfigTest
      Use the shell command to set/get the override LocaleConfig
Change-Id: I1bfd5431302d4d31b0f8891dd5a7419641657416