[Provider Model] Add progress bar to internet panel

- Show progress bar when Wi-Fi scanning

- Show "Searching for networks..." sub-title when Wi-Fi scanning

- Remove "Wi-Fi" from searching networks string

Bug: 178774497
Test: manual test
atest -c InternetConnectivityPanelTest
make RunSettingsRoboTests ROBOTEST_FILTER=PanelFragmentTest

Change-Id: Ic05b939bef3b106845fe90db41eb09f0e15756f4

tests/robotests/src/com/android/settings/panel/FakePanelContent.java

@@ -48,6 +48,7 @@ public class FakePanelContent implements PanelContent {
     private int mViewType;
     private boolean mIsCustomizedButtonUsed = false;
     private CharSequence mCustomizedButtonTitle;
+    private boolean mIsProgressBarVisible;
 
     @Override
     public IconCompat getIcon() {
@@ -117,4 +118,13 @@ public class FakePanelContent implements PanelContent {
     public void setCustomizedButtonTitle(CharSequence title) {
         mCustomizedButtonTitle = title;
     }
+
+    @Override
+    public boolean isProgressBarVisible() {
+        return mIsProgressBarVisible;
+    }
+
+    public void setIsProgressBarVisible(boolean isProgressBarVisible) {
+        mIsProgressBarVisible = isProgressBarVisible;
+    }
 }

tests/robotests/src/com/android/settings/panel/PanelFragmentTest.java

@@ -35,6 +35,7 @@ import android.view.LayoutInflater;
 import android.view.View;
 import android.widget.Button;
 import android.widget.LinearLayout;
+import android.widget.ProgressBar;
 import android.widget.TextView;
 
 import androidx.core.graphics.drawable.IconCompat;
@@ -308,4 +309,25 @@ public class PanelFragmentTest {
         assertThat(seeMoreButton.getVisibility()).isEqualTo(View.VISIBLE);
         assertThat(seeMoreButton.getText()).isEqualTo("test_title");
     }
+
+    @Test
+    public void onProgressBarVisibleChanged_isProgressBarVisible_showProgressBar() {
+        final ActivityController<FakeSettingsPanelActivity> activityController =
+                Robolectric.buildActivity(FakeSettingsPanelActivity.class);
+        activityController.setup();
+        final PanelFragment panelFragment = (PanelFragment)
+                Objects.requireNonNull(activityController
+                        .get()
+                        .getSupportFragmentManager()
+                        .findFragmentById(R.id.main_content));
+
+        final ProgressBar progressBar = panelFragment.mLayoutView.findViewById(R.id.progress_bar);
+
+        mFakePanelContent.setIsProgressBarVisible(true);
+        verify(mFakePanelContent).registerCallback(mPanelContentCbs.capture());
+        final PanelContentCallback panelContentCallbacks = mPanelContentCbs.getValue();
+        panelContentCallbacks.onProgressBarVisibleChanged();
+
+        assertThat(progressBar.getVisibility()).isEqualTo(View.VISIBLE);
+    }
 }