Update Gradle, AGP & Kotlin

uhabits-android/src/androidTest/java/org/isoron/uhabits/acceptance/steps/ListHabitsSteps.kt

@@ -53,6 +53,7 @@ object ListHabitsSteps {
                 clickViewWithId(R.id.action_filter)
                 CommonSteps.clickText(R.string.hide_completed)
             }
+            else -> throw RuntimeException()
         }
         device.waitForIdle()
     }

uhabits-android/src/main/java/org/isoron/uhabits/activities/habits/show/ShowHabitActivity.kt

@@ -220,6 +220,7 @@ class ShowHabitActivity : AppCompatActivity(), CommandRunner.Listener {
                 ShowHabitMenuPresenter.Message.COULD_NOT_EXPORT -> {
                     showMessage(resources.getString(R.string.could_not_export))
                 }
+                else -> {}
             }
         }