Proto commits in didi/booster

These 5 commits are when the Protocol Buffers files have changed:

Commit:70179e8
Author:johnsonlee
Committer:Johnson Lee

Improve `booster-aapt2` compatibility

The documentation is generated from this commit.

Commit:12d4c49
Author:johnsonlee

Fix AAPT2 compatibility for Android gradle plugin 3.1.0

Commit:b237bc9
Author:johnsonlee

Fix aapt2 parsing issue for Android gradle plugin 3.4+

Commit:60c52cd
Author:johnsonlee

Fix CI error: Cannot run program "protoc": error=2, No such file or directory

This commit does not contain any .proto files.

Commit:da9aec8
Author:johnsonlee

Fix issue #5: retains referenced symbols