Apply signed config on package upgrade/install.

Signature check is not implemented yet, so no configuration can be
applied yet.

Tested with CTS test & follow up changes in later CLs.

For future reference:
Test: atest CtsSignedConfigHostTestCases

Bug: 110509075
Change-Id: I2d2f15d38ec0f1755e21e6e5ab5c82d94aa592a4
4 files changed