Add SDK extension versions to dumpstate header

Example output:
    Network: (unknown)
    Module Metadata version: 30
    Extension versions [r=12 s=45]

Bug: 185376949
Test: install test_com.android.sdkext && inspect adb bugreport
Change-Id: Ie85ef2226a54da571d3bd8c905fbf5e12465cdc2