Keep track of admin actions for DO disclosures

This CL adds bookkeeping to DPMS which will allow us to tell the user
in the Settings UI whether/when the admin requested a bug report or
retrieved logs from the device.

Bug: 32692748
Test: Full DevicePolicyManagerTest unit test coverage; end-to-end tests
        will follow as Settings CTS verifier tests

Change-Id: I89728fce4b7e0ff061b354c73caf3742e95a3a3e