Adding support for Activity Segments

Change-Id: If1355cb374384b54a236f335a649aac00b30f4a9
Updating samples for naming changes

Change-Id: Id463c16fcdaa35e59a0bce463ded2ffbadc210c4
Updating subscribe flow and also cleaning up cancel calls for clarity

Change-Id: I60f15ac03754e76e12c5e83264af9b3227abddb7
Adding documentation snippet markup, and correcting scope list for BasicHistorySessions

Change-Id: I45fba1a8a300cb29bf85106cc7780d7da74f36eb
Correcting the Copyright text

Change-Id: Ieff506b6a4547ed850bed40f5220a2c4d8843136
Adding documentation snippets for auth code

Change-Id: I12ec4b91f3abd4ff04b41273e9a59967e6a0677e
Merge "Adding documentation snippets for auth code"
Updating samples to support SDKs 9 to 19 instead of the L preview

Change-Id: Icd722cd6e68afea8ac1668b57c9b68b030eb6945
Updating Google Play Services version number

Change-Id: I5015a0e7e37d52db5393ef360f3b2177b9a7c43f