Use generated merged annotations.zip in SDK build

The framework-doc-stubs is being transitioned to use module jar stub
source as input, at which point it will stop producing correct
annotations.zip files. Replace the annotations zip file in the sdk
with the one generated from all the constituent parts.

Bug: 187397779
Test: diff sdk.zip before && after (only whitespace diffs in annotations)
Change-Id: I56b22bf4909105a2720221c8de35b517a6e66a3c
2 files changed