Summary: Adding context [PreferenceManager.getDefaultSharedPreferencesName](https://developer.android.com/reference/android/preference/PreferenceManager.html#getDefaultSharedPreferences(android.content.Context)) by default. ## Changelog Adding context default shared preference by default. Pull Request resolved: https://github.com/facebook/flipper/pull/454 Reviewed By: jknoxville Differential Revision: D15759223 Pulled By: passy fbshipit-source-id: d0770444ce2ea43e2c9bfdc9969532d330f71488