Updated target SDK from 28 to 29.

Merged the following change from internal source: cl/305938566

Do not use EXTRA_IS_HANDOVER for API levels 28 and above

When targeting API level 29, this field becomes blacklisted.
Since the Handover feature is officially supported via a public API since
API level 28, we do not need to check for the internal field when the API level
is 28+.

go/forrest_run/L11100000565062425
BUG: 143990966
Test: manual and CTS tests.

Change-Id: Ib3fda29b4d5714efc52b29f49ca4a9a310584fff