Show ProgressDialog when waiting for radio to turn on when provisioning.

Turning on the cellular radio when user selects the provisioning notification
can take 30-60s so a UI is needed to keep the user informed that the radio is
coming up. This is only for provisioning APN support (only AT&T tablets now).

bug:15990642
Change-Id: Ibea894ee934bae2045c0462ae79bfa39d0ef3f05

telephony/java/com/android/internal/telephony/DctConstants.java

@@ -99,6 +99,7 @@ public enum Activity {
     public static final int EVENT_PROVISIONING_APN_ALARM = BASE + 39;
     public static final int CMD_NET_STAT_POLL = BASE + 40;
     public static final int EVENT_DATA_RAT_CHANGED = BASE + 41;
+    public static final int CMD_CLEAR_PROVISIONING_SPINNER = BASE + 42;
 
     /***** Constants *****/