Fix incorrect minor version for Proximity Kit lib.

In order to use beacons the minimum SDK needs to be 18, not 9.
Fix incorrect manifest file.

This is not required for Proximity Kit. The `launchMode` setting is
specific to how this sample app works. In order to properly handle the
main activity UI's list, only a single instance should be created at a
time.

This was missing from the initial release.
Improve debug messages to include the state.
Fix :bug: where the UI list was not cleared.

Clear the internal row map when the activity manager is stopped. This
fixes a bug where after starting the `ProximityKitManager` a second time
the UI list is not updated. This happened because the inner row map was
not cleared, so the beacon was thought to already have been seen, thus
it was not re-added to the view; however the view itself was already
cleared.
Use the 0.2.0 version.