Adds LastLocationRequest SystemApi

Creates a new LastLocationRequest object similar to LocationRequest,
specifically for useage with the getLastLocation() APIs. This allows
SystemApi clients to pass in important parameters like
locationSettingsIgnored, etc...

Bug: 173666111
Test: manual + presubmits
Change-Id: I2e0253e5275d9d17cfb5a9243de0ef12ab33348c