Moves all compatibility flags to ConnectivityCompatChanges.java

ConnectivityCompatChanges.java becomes the centralized place for all the
CompatChanges used in the Connectivity module. By putting all the
CompatChanges here, we are able to manage them under a single
platform_compat_config.

Bug: 268440216
Test: atest FrameworksNetTests
Change-Id: I3e17af545718073d7d1c96e27298e7790563fd33
9 files changed