[Browser2] Update target_sdk version to 29 (Q) am: 8a68fdaf04 am: 7746aa5060 am: 3a40639240 Original change: https://android-review.googlesource.com/c/platform/packages/apps/Browser2/+/1333187 Change-Id: I2a3838541dbdff2dd7483caf4169030e602cbc9e