When the UseGoma flag is set, put all rules except the C compilation
rule in an externally defined local_pool, which will have been created
by kati. The gomacc wrapper will already be in the CC_WRAPPER
environment variable.
Bug: 31142427
Change-Id: I699d4edff2e302eee398dad8692ceb14721a628c
And install the tools into a more obvious location. soong_env is not
moved, since we need it to exist early, so that we can use it in
soong.bash in case there's a build failure.
Change-Id: I9bd1fa320d84d180b2cf3deb90782d380666f7a6