Refactor image blurring to use RenderScript for improved performance and quality

- Replaced custom fast blur implementation with RenderScript-based Gaussian blur in BlurredAvatarBackground and AppearanceScreen.
- Updated image processing logic to scale down bitmaps before applying blur for efficiency.
- Simplified blur logic by removing unnecessary pixel manipulation methods.
- Enhanced media preview handling in OtherProfileScreen to utilize new Gaussian blur function.
- Improved code readability and maintainability by consolidating blur functionality.

app/src/main/java/com/rosetta/messenger/data/ReleaseNotes.kt

@@ -28,4 +28,8 @@ object ReleaseNotes {
 
     fun getNotice(version: String): String =
         RELEASE_NOTICE.replace(VERSION_PLACEHOLDER, version)
+
+    /** Hash of current notice text — used to re-send if text changed within the same version */
+    val noticeHash: String
+        get() = RELEASE_NOTICE.hashCode().toString(16)
 }