Remove ref to LatinImeLogger preference.

This is a bug; the ResearchLogger uses ResearchSettings.readResearchLoggerEnabledFlag() instead,
which the user cannot change.  (We assume they will just switch to a different keyboard.)

Change-Id: Ib5731c9eeb2bc29d9cf8608033326674f5eb6f7b

java/src/com/android/inputmethod/research/ResearchLogger.java

@@ -118,7 +118,6 @@ public class ResearchLogger implements SharedPreferences.OnSharedPreferenceChang
     private static final boolean FEEDBACK_DIALOG_SHOULD_PRESERVE_TEXT_FIELD = false;
     /* package */ static boolean sIsLogging = false;
     private static final int OUTPUT_FORMAT_VERSION = 5;
-    private static final String PREF_USABILITY_STUDY_MODE = "usability_study_mode";
     // Whether all words should be recorded, leaving unsampled word between bigrams.  Useful for
     // testing.
     /* package for test */ static final boolean IS_LOGGING_EVERYTHING = false
@@ -481,10 +480,6 @@ public class ResearchLogger implements SharedPreferences.OnSharedPreferenceChang
         if (key == null || prefs == null) {
             return;
         }
-        sIsLogging = prefs.getBoolean(PREF_USABILITY_STUDY_MODE, false);
-        if (sIsLogging == false) {
-            abort();
-        }
         requestIndicatorRedraw();
         mPrefs = prefs;
         prefsChanged(prefs);