Add ro.bootimage.* property contexts

In addition, allow shell to read this property.

Test: getprop -Z
Test: cts-tradefed run cts -m CtsGestureTestCases
      and check /sdcard/device-info-files/PropertyDeviceInfo.deviceinfo.json

Bug: 169169031
Change-Id: Ib71b01bac326354696e159129f9dea4c2e918c51
6 files changed