telecom register-sim-phone-account for secondary users.

bug: 121100405
Test: cts-tradefed run cts-dev -a arm64-v8a -m CtsTelecomTestCases -t android.telecom.cts.RemoteConferenceTest#testRemoteConferenceCallbacks_ConferenceableConnections

... or:

$ adb shell am switch-user 11
$ adb shell dumpsys user | grep serial
  UserInfo{0:null:13} serialNo=0
  UserInfo{11:nick:10} serialNo=134
$ m cts
$ adb install -g out/target/product/generic_arm64/testcases/CtsTelecomTestCases/CtsTelecomTestCases.apk
$ adb shell telecom register-sim-phone-account android.telecom.cts/android.telecom.cts.CtsRemoteConnectionService xtstest_REMOTE_CALL_PROVIDER_ID 134 CTSRemoteConnectionService tel:666-TEST

Change-Id: Iecb3a5aa3999d8cc7bd7103815136dde38c49f06