API Review Feedbacks

1) Rethrow the remoteException instead of returning empty string
 for CarrierConfigManager#getDefaultCarrierServicePackageName()

2) Flip documentation to use “valid” instead of “invalid” for
 ModemActivityInfo.isValid()

Bug: 147804136
Test: Treehugger; Cts
Change-Id: I595837dfb24a09c68e33a732aa24b5b25ff28ac0

telephony/java/android/telephony/CarrierConfigManager.java

@@ -4110,6 +4110,7 @@ public class CarrierConfigManager {
         } catch (RemoteException ex) {
             Rlog.e(TAG, "getDefaultCarrierServicePackageName ICarrierConfigLoader is null"
                     + ex.toString());
+            ex.rethrowAsRuntimeException();
         }
         return "";
     }

telephony/java/android/telephony/ModemActivityInfo.java

@@ -199,7 +199,7 @@ public final class ModemActivityInfo implements Parcelable {
     }
 
     /**
-     * Indicate if the ModemActivityInfo is invalid due to modem's invalid reporting.
+     * Indicates if the modem has reported valid {@link ModemActivityInfo}.
      *
      * @return {@code true} if this {@link ModemActivityInfo} record is valid,
      * {@code false} otherwise.