Add additional mocking for Context innards

Test: as follows
    - built
    - flashed
    - booted
    - runtest frameworks-net passes
    - cherry-picked to master and verified there as well
Bug: 32163131
Bug: 32561414

Merged-In: I2695841bfc31280060754132e589af1ca95911da
Merged-In: I9a05f34035a15b233a44d517f2b2426481679974
Change-Id: I0b5b1b12d55547d08c332c7d274f19f0023a7b07
(cherry picked from commit ec37275e)