[ Merge of http://go/wvgerrit/163900/ ]
ATSC licenses can be saved by calling
MediaDrm#setPropertyString("storeAtscLicense",<value>)
where <value> is
"<atsc-key-set-ID>:<license-file-data in Base64 format>"
Before storing an ATSC license a session must be opened and the
ATSC mode must be enabled.
Use MediaDrm#setPropertyString("atscMode","enable");
Bug: 176871821
Test: WV Unit/integration/Luci tests
Test: libwvdrmdrmplugin_hal_test
Test: GtsMediaTestCases
Change-Id: Iec2a8b7f87b1122395d06856202278b92316fdfe
1e15b36b1a