Android p preview 4
Merge remote-tracking branch upstream-master into master

* origin/upstream-master: (43 commits)
  Allow --worker_max_instances to take MnemonicName=value to specify max for each named worker.
  Clean up code that directly imports nested classes like Builder, Entry, etc.
  Clean up code that directly imports nested classes like Builder, Entry, etc.
  Clean up code that directly imports nested classes like Builder, Entry, etc.
  Remove use of bare Immutable{List,Map,Set} Builder classes.
  Relax the assertion in Desugar for checking the calls to $closeResource(...). It is possible that $closeResource(...) is not used as the calls to it might be eliminated by some optimization tools, such as Proguard.
  Make attempting to change --config in invocation policy an error.
  Remove alphabetical sorting of options in the canonical list.
  Remove some deprecated resources flags.
  Remove category checking from incompatible changes.
  Support source versions newer than 8 in Bazel's annotation processors
  stub simple core library bridge methods that only differ in return type RELNOTES: None.
  Reflect core library moves in super calls, even in default method stubs.  Always generate default method stubs for emulated methods. RELNOTES: None.
  Make KeepScanner tool search classpath for nearest definition of each member reference, instead of potentially referring to a subtype. Refactor desugar's class loading machinery and related code into a separate package for easier reuse in this tool. RELNOTES: None.
  Minor fixes to KeepScanner tool: - use Guava to read zip entries - Fix keep rules emitted for constructors RELNOTES: None.
  Support custom implementations of emulated core interface methods RELNOTES: None.
  tests,windows: enable android.desugar.runtime
  emulate dynamic dispatch of emulated default interface methods RELNOTES: None.
  Android desugar config options to exclude methods from interface emulation RELNOTES: None.
  send invocations to emulated interfaces through dispatch helper. fix logic for implementing emulated interfaces. RELNOTES: None.
  ...

BUG: none
Test: existing