Fix usages of PackageManager APIs in Telephony

Remove usages of the hidden PackageManager#*asUser methods from
Telephony, and add some unit tests to verify the functionality.

Test: atest FrameworksTelephonyTests
Test: atest TelephonyCommonTests
Bug: 146834818
Change-Id: I2e2ec2c421773e3ff58556373896238e1ff0678a
diff --git a/tests/TelephonyCommonTests/Android.bp b/tests/TelephonyCommonTests/Android.bp
index 16189c8..61c3829 100644
--- a/tests/TelephonyCommonTests/Android.bp
+++ b/tests/TelephonyCommonTests/Android.bp
@@ -38,7 +38,7 @@
 
     // Uncomment this and comment out the jarjar rule if you want to attach a debugger and step
     // through the renamed classes.
-    //platform_apis: true,
+    // platform_apis: true,
 
     libs: [
         "android.test.runner",