Code optimization and refactor

[sameerasw]

This pull request mainly focuses on code cleanup, formatting improvements, and minor refactoring in both the Gradle build script and the AppLockActivity and AppUpdatesActivity classes. The changes aim to improve code readability, maintainability, and consistency, with no significant changes to core logic or functionality.

Build script improvements

• Removed the redundant kotlin.android plugin from app/build.gradle.kts and added a new compiler argument for annotation defaults. [1] [2]

AppLockActivity refactoring and cleanup

• Improved imports order and replaced direct android.os.Build references with imported Build for better readability. [1] [2]
• Reformatted long lines and method calls for better readability, especially for color selection, padding, and biometric prompt initialization. [1] [2] [3]
• Updated activity transition handling to use overrideActivityTransition for Android 14+ and suppressed deprecation warnings for older versions.
• Added @Deprecated annotation to onBackPressed override and ensured consistent handling of back navigation.

AppUpdatesActivity formatting and minor refactoring

• Cleaned up and reorganized imports in AppUpdatesActivity.kt, removing unused imports and grouping related components.
• Reformatted long lines and argument lists for improved readability throughout the file, especially in UI component initialization and callback lambdas. [1] [2] [3] [4] [5] [6] [7] [8] [9]