Support launching wallet on double tap.

Reads user settings on whether to launch camera or wallet on power
button double tap. If wallet has the setting, send PendingIntent retrieved from
QuickAccessWalletClient.getGestureTargetActivityPendingIntent.
Demo video: https://drive.google.com/file/d/1-KswX5uhFQ9ROjaStQIAG_GDVGWF96sb/view?usp=drive_link&resourcekey=0-u6zHUTQzCqctSi_CQp2mMA

Note: this is the same change as ag/30412668, but has been separated
from that topic since the other change was causing build failures.

Bug: 378469025
Test: atest GestureLauncherServiceTest
Test: Manual testing: double power settings are immediately updated and reflected
after being toggled
Flag: android.service.quickaccesswallet.launch_wallet_option_on_power_double_tap

Change-Id: I3ad5d7285384db7aebd8a31772097edaf2462e49