Fix test app installation issue in e2e test.

The snippet and data provider app are signed as system app to access
system API. We need to use adb remount, adb push approach to install
instead of adb install.

Test: atest -v CtsNearbyMultiDevicesTestSuite
Bug: 214015364
Ignore-AOSP-First: nearby_not_in_aosp_yet
Change-Id: I4f3b0a3c2bea8bf4b6c96a67c28cf83babd65e46
1 file changed