Update ActionDisabledByAdminDialogHelper

- For managed devices, "Learn more" takes the user to a support
page
- Put back the "If you have questions, contact your IT admin"
dialog content text
- Update header to 'Blocked by your IT admin' for managed devices

Fixes: 184107103
Test: manual
Test: atest ActionDisabledByAdminDialogHelperTest
Test: atest ActionDisabledLearnMoreButtonLauncherImplTest
Change-Id: Ie5b8a21b9ba295435d5709f9b0374035141d319a

tests/robotests/Android.bp

@@ -72,10 +72,11 @@ android_robolectric_test {
 
     static_libs: [
         "SettingsLib-robo-testutils",
-	"android-support-annotations",
+        "android-support-annotations",
         "androidx.test.core",
         "androidx.test.runner",
         "androidx.test.ext.junit",
+        "androidx.test.espresso.core",
     ],
 
     libs: [