CaptivePortalData: use CharSequence in VenueFriendlyName API

Following up on feedback from API council, change the String type
to CharSequence in the get and set Venue friendly name API.

Bug: 179163405
Test: atest ConnectivityServiceTest CtsNetTestCasesLatestSdk:CaptivePortalDataTest
Test: atest NetworkNotificationManagerTest NetworkMonitorTest
Change-Id: Ia63974cd2ff5975bde410eb93731d4b1def36d19
diff --git a/framework/api/system-current.txt b/framework/api/system-current.txt
index a98f14e..54b3f56 100644
--- a/framework/api/system-current.txt
+++ b/framework/api/system-current.txt
@@ -18,7 +18,7 @@
     method public long getRefreshTimeMillis();
     method @Nullable public android.net.Uri getUserPortalUrl();
     method public int getUserPortalUrlSource();
-    method @Nullable public String getVenueFriendlyName();
+    method @Nullable public CharSequence getVenueFriendlyName();
     method @Nullable public android.net.Uri getVenueInfoUrl();
     method public int getVenueInfoUrlSource();
     method public boolean isCaptive();
@@ -40,7 +40,7 @@
     method @NonNull public android.net.CaptivePortalData.Builder setSessionExtendable(boolean);
     method @NonNull public android.net.CaptivePortalData.Builder setUserPortalUrl(@Nullable android.net.Uri);
     method @NonNull public android.net.CaptivePortalData.Builder setUserPortalUrl(@Nullable android.net.Uri, int);
-    method @NonNull public android.net.CaptivePortalData.Builder setVenueFriendlyName(@Nullable String);
+    method @NonNull public android.net.CaptivePortalData.Builder setVenueFriendlyName(@Nullable CharSequence);
     method @NonNull public android.net.CaptivePortalData.Builder setVenueInfoUrl(@Nullable android.net.Uri);
     method @NonNull public android.net.CaptivePortalData.Builder setVenueInfoUrl(@Nullable android.net.Uri, int);
   }