Fix lint issues

app/src/main/java/ch/dissem/apps/abit/AbstractItemListFragment.kt

@@ -27,7 +27,7 @@ import ch.dissem.apps.abit.listener.ListSelectionListener
 /**
  * @author Christian Basler
  */
-abstract class AbstractItemListFragment<L, T> : ListFragment(), ListHolder<L> {
+abstract class AbstractItemListFragment<in L, T> : ListFragment(), ListHolder<L> {
     /**
      * The fragment's current callback object, which is notified of list item
      * clicks.

app/src/main/java/ch/dissem/apps/abit/util/PRNGFixes.java

@@ -39,6 +39,7 @@ import java.security.Security;
  * @see <a href="http://android-developers.blogspot.ch/2013/08/some-securerandom-thoughts.html">
  * http://android-developers.blogspot.ch/2013/08/some-securerandom-thoughts.html</a>
  */
+@SuppressWarnings("WeakerAccess")
 public final class PRNGFixes {
 
     private static final int VERSION_CODE_JELLY_BEAN = 16;