Remove extra space in SPN

For some SIM cards, SPN is returned with trailing spaces.
This causes extra spaces in SPN string when "Wi-Fi Calling" suffix is applied.

Change-Id: I4722441ab54dbf2106c2d3ecdf29ed1ce1253867
diff --git a/src/java/com/android/internal/telephony/gsm/GsmServiceStateTracker.java b/src/java/com/android/internal/telephony/gsm/GsmServiceStateTracker.java
index 811fb80..0976541 100755
--- a/src/java/com/android/internal/telephony/gsm/GsmServiceStateTracker.java
+++ b/src/java/com/android/internal/telephony/gsm/GsmServiceStateTracker.java
@@ -648,7 +648,7 @@
                     com.android.internal.R.string.wfcSpnFormat).toString();
             showPlmn = false;
             showSpn = true;
-            spn = String.format(format, spn);
+            spn = String.format(format, spn.trim());
         } else if (mSS.getVoiceRegState() == ServiceState.STATE_POWER_OFF
                 || (showPlmn && TextUtils.equals(spn, plmn))) {
             // airplane mode or spn equals plmn, do not show spn