Refactor emulator.install to use Adb.install for consistency

The emulator.install command has custom code for installing APKs, unlike device.install which uses Adb.install. This custom code is almost identical to Adb.install except that it retries the installation in certain failure cases.

The custom code is a fix for CB-9119. The related Android bug which is mentioned (https://code.google.com/p/android/issues/detail?id=10255) refers to Android 2.2, for which support has long been dropped.

Ideally, we should refactor this code to use Adb.install and create less overhead for maintenance.