Wifi: Use bss->age identifier for wifi scan results

This value will be used as "timestamp" and Google Play Services
uses this value for identifying sane wifi scan items.

The current timestamp (tsf=) has a different meaning, which causes
the Google Location Resolver to ignore all wifi scan entries and
therefore no location can be resolved.

This solution is already done on batched result parsing, but
missing on the traditional scans.

Change-Id: I36a1aeb666379e6a010298f09161e971012db83f
Revert "Add UUID (re-)scan support for vold-mounted volume (1/2)"

This reverts commit a69c9194607887542c4e4d1d00039ee363fbb6c1.

Change-Id: I259079018edda8aae8fc536c100d61c4272af9a1
MountService: Handle UUID in list response

Change-Id: Ifee8905ae01c17c79b218ec131650c25f6e977d6