stub out injectTime API as we should not handle that

We should no longer accept the NTP injection from AFW
as we have our XC handling the NTP update.

Bug: 147339217
Change-Id: I820e78d4de4fb97dd1f07455c651a37b5f0040d6
CRs-Fixed: 2595204
Test: build pass and verify pass
diff --git a/msm8998/android/Gnss.cpp b/msm8998/android/Gnss.cpp
index 9b2e7dd..078bde5 100644
--- a/msm8998/android/Gnss.cpp
+++ b/msm8998/android/Gnss.cpp
@@ -241,14 +241,7 @@
 
 Return<bool> Gnss::injectTime(int64_t timeMs, int64_t timeReferenceMs,
                               int32_t uncertaintyMs) {
-    ENTRY_LOG_CALLFLOW();
-    GnssInterface* gnssInterface = getGnssInterface();
-    if (nullptr != gnssInterface) {
-        gnssInterface->injectTime(timeMs, timeReferenceMs, uncertaintyMs);
-        return true;
-    } else {
         return false;
-    }
 }
 
 Return<void> Gnss::deleteAidingData(IGnss::GnssAidingData aidingDataFlags)  {