AIDEGen: Check the target is the main project by the target sequence

The main project would be the Android repo root folder or the first
project that users key in with command line.

Bug: 137507006
Test: 1. aidegen Settings SettingsLib
      2. Backup the iml files under Settings and SettingsLib modules.
      3. m aidegen;aidegen-dev Settings SettingsLib
      2. Check the new iml files are the same with the older.

Change-Id: I3b66258569d16b719f2d723f33e5de8b32cc99c8
4 files changed