Update PhoneStateListener#onCallStateChanged Javadoc.

While the doc suggested that the phone number was "incoming" (e.g.
only populated for incoming calls), it should also be populated for
outgoing calls.

Bug: 67748129
Test: Verified expected behavior on Taimen running OC-MR1, added CTS
test (see other CL in this topic)
Change-Id: I1ddd9c042f287953358a794b91b2af5ed6f5b597
Merged-In: I1ddd9c042f287953358a794b91b2af5ed6f5b597