Launch wallet app on double tap option.

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.

Bug: 378469025
Test: atest GestureLauncherServiceTest
Test: Manual testing (double-tap power button with both settings and
ensure camera/wallet are appropriately launched.)
Flag: android.service.quickaccesswallet.launch_wallet_option_on_power_double_tap
Change-Id: Id14db9f33cd6f0de7527b06747d9520c3478a742

Change-Id: I808769cc5ee012a172427f98f585c025c516a386