Issue #1 is solved by adding @deprecated javadoc to UnitSystem.java file

src/main/java/de/dennisguse/opentracks/settings/UnitSystem.java

@@ -20,6 +20,9 @@ public int getPreferenceId() {
         return preferenceIdentifier;
     }
 
+    /**
+     * @deprecated (when, why, etc...)
+     */
     @Deprecated //TODO used to initialize before loading from preferences; should be loaded first
     public static UnitSystem defaultUnitSystem() {
         return METRIC;