write_version_header: don't try to resolve the tag
write_version_header: don't try to resolve the tag

This change makes the version code always v9.0-abcdef,
regardless of building on a tag or on a branch. This makes
the version string more consistent in the various cases.
Removing the query of the tag avoids circular problems when
releasing the SDK where the script queries the tag by looking
at CHANGELOG but the tag doesn't exist yet.


Bug: 198293659
Change-Id: I91f40c1e14656c8282a98a6ee75162623f2fae03

google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto