Remove hidden API usage from ProxyTracker

Connectivity mainline module cannot use HandlerExecutor because it
is a hidden API. So, replace it with alternative.

Bug: 177035719
Test: FrameworksNetTests
Change-Id: I228a8a2e3479b0af1e977d13f877a565f0789a7e
1 file changed
tree: 7a0b4929cace98618c13ee806759fe078daeb536
  1. core/
  2. framework/
  3. service/
  4. services/
  5. tests/
  6. OWNERS