Delete unused getNamespace method

Bug: 156613910
Test: layoutlib tests
Change-Id: I4f1a45f55e31d99903bf0cdac56c86a8d553a32c
(cherry picked from commit 40ef608929b7d16b35c5837bd9ba73bbbe759699)
Merged-In: I4f1a45f55e31d99903bf0cdac56c86a8d553a32c
4 files changed