User consent for Logcat data access

The LogcatManagerService checks if logd access is coming
from background or foreground.

If the requester is foreground, the LogcatManagerService
generates a notification to get user consent. If the user grants access,
the LogcatManagerService approves logd access. If the user
does not grant access, the LogcatManagerService denies logd access.

If the requester is background, the LogcatManagerService waits
to observe process status change. If the
process status updates to foreground from background,
LogcatManagerService sends a notification to get user consent.
If the process remains background, the LogcatManagerService denies logd access.

This codebase is the continuity of the implementation ag/16618162 to
obtain user consent.

Bug: 193708292
Test: CtsVerifier
Ignore-AOSP-First: pending fix for logcat privacy issue

Change-Id: I4103c72daebdea5e8f04ab4901c05be2f1aefc84