Remove unnecessary api version checks in WindowUtil (#1163)

app/src/main/java/org/thoughtcrime/securesms/conversation/v2/WindowUtil.java

@@ -38,14 +38,10 @@ public final class WindowUtil {
   }
 
   public static void setNavigationBarColor(@NonNull Window window, @ColorInt int color) {
-    if (Build.VERSION.SDK_INT < 21) return;
-
     window.setNavigationBarColor(color);
   }
 
   public static void setLightStatusBarFromTheme(@NonNull Activity activity) {
-    if (Build.VERSION.SDK_INT < 23) return;
-
     final boolean isLightStatusBar = ThemeUtil.getThemedBoolean(activity, android.R.attr.windowLightStatusBar);
 
     if (isLightStatusBar) setLightStatusBar(activity.getWindow());
@@ -53,20 +49,14 @@ public final class WindowUtil {
   }
 
   public static void clearLightStatusBar(@NonNull Window window) {
-    if (Build.VERSION.SDK_INT < 23) return;
-
     clearSystemUiFlags(window, View.SYSTEM_UI_FLAG_LIGHT_STATUS_BAR);
   }
 
   public static void setLightStatusBar(@NonNull Window window) {
-    if (Build.VERSION.SDK_INT < 23) return;
-
     setSystemUiFlags(window, View.SYSTEM_UI_FLAG_LIGHT_STATUS_BAR);
   }
 
   public static void setStatusBarColor(@NonNull Window window, @ColorInt int color) {
-    if (Build.VERSION.SDK_INT < 21) return;
-
     window.setStatusBarColor(color);
   }