Expose additional Cronet APIs in AOSP.

This is required to provide a reasonably feature-comnplete
implementation of current org.chromium.net APIs on top of
android.net.http. The main targets for this change are gRPC (mostly
bidirectional streaming) and prospective early adopters.

Test: m
API-Coverage-Bug: 251012627
Change-Id: I66341581501090641c7eea32de5a5b8453cd97d4
1 file changed