CtsWifiTestCases: don't disable location upon test completion

target_preparer in AndroidTest.xml always disables
location mode after CtsWifiTestCases completes, even
if location was enabled at the start of the test.

Convert this logic to Java code so that we can keep location
mode enabled if it was enabled at the start of the test.

Bug: 160940810
Test: atest CtsWifiTestCases
Change-Id: I3f7a57d4e3d72d1587b96433eba2b06217ff5dff
Merged-In: I3f7a57d4e3d72d1587b96433eba2b06217ff5dff
25 files changed