Revert "Add OWNERS block to prevent the tree from mooving during migration." Migration of frameworks/base/packages/Tethering is complete, removing the OWNERS block. This reverts commit 1623eb61d5e753ca7a2c48bf41eefc235d3f79b1. BUG: 167962976 Test: TH Change-Id: Ic89c084604788b4d41cf854e5015c8ce7791c64d