Add command line strictness to VTS

Was compile time, making command line for
easier test team usage of the stronger
test you can do with GNSS signal available.

Also ensuring location calculated correctly after
a delete all (when -agps present), and faster tests.

Bug: 36356863
Test: Verified command line switches work as expected
  on a Pixel

Change-Id: I4aa92ff2ca664b1c93bbc9ac154d27063160acf2