Revert "Use "gfxstream" namespace"

Revert submission 2513870-gfxstream-namespace-2

Reason for revert: This breaks the MacOS gfxstream build.

Reverted changes: /q/submissionid:2513870-gfxstream-namespace-2
Bug: 276321260

Change-Id: I6ab589a1308cce5fd467f8e57c158a8179aeb133
1 file changed