Remove duplicate strings.

"Yes" and "no" were redefined many times with no clear benefit, so this
consolidates them into one definition.

Bug: 243843096
Test: Build, install, and open the Settings app
Test: atest SettingsRoboTests
Change-Id: I5f84d09f223efd478461ded93aeac82bf7b128d8

tests/robotests/src/com/android/settings/connecteddevice/NfcAndPaymentFragmentControllerTest.java

@@ -92,13 +92,13 @@ public class NfcAndPaymentFragmentControllerTest {
     public void getSummary_nfcOn_shouldProvideOnSummary() {
         mShadowNfcAdapter.setEnabled(true);
         assertThat(mController.getSummary().toString()).contains(
-                mContext.getString(R.string.switch_on_text));
+                mContext.getString(R.string.on));
     }
 
     @Test
     public void getSummary_nfcOff_shouldProvideOffSummary() {
         mShadowNfcAdapter.setEnabled(false);
         assertThat(mController.getSummary().toString()).contains(
-                mContext.getString(R.string.switch_off_text));
+                mContext.getString(R.string.off));
     }
 }