Add intent to clear app cache

Adds a new public API intent action that should be used to launch a
dialog that prompts the user to clear app caches.
The intent can be used by apps holding MANAGE_EXTERNAL_STORAGE
permission or with OP_MANAGE_EXTERNAL_STORAGE allowed

Bug: 144341120
Test: build

Change-Id: Icc6de16da4f892f1ed46ffc89e51071647a17400