Stability fix for Native Binder Stats

Ensure interfaceDescriptor is initialised in all code paths. Report
binder stats before sending the reply. This may delay some binder
responses but should reduce the chance of a race condition which
may be causing b/421429613.

Test: v2/pixel-pts/device-presubmit-new-global1
Bug: 421429613
Bug: 299356196
Flag: build.RELEASE_LIBBINDER_BINDER_OBSERVER
Change-Id: Ie6e392b6c5dde701f1ddb3993bc374db9e8e5b97