Enable isolated process to use graphics allocator

Add an LLNDK API for isolated process usage.

Bug: 268016157
Bug: 269675258
Test: Manual - Service can be added with allowIsolated set to true.
Change-Id: I9d3c39e313978ccd6b01574b5533530d4f959904
Merged-In: I9d3c39e313978ccd6b01574b5533530d4f959904