Develop - Shut up bug fix

[sameerasw]

This pull request introduces a new version of the app (15.4) and includes improvements to app flow handling, particularly around usage stats and the "Shut Up" feature. The most significant changes involve better management of app package transitions, especially when using usage access, and a tweak to service startup logic.

App flow and usage stats handling:

• Added a new currentUsageStatsPackage property to AppFlowHandler to separately track the package detected via usage stats. This allows for more accurate handling of app transitions when usage access is enabled.
• Modified the logic in AppFlowHandler.handleAppChanged to ensure that checkShutUpRestore is called correctly when the package detected by usage stats changes, and to update currentPackage only when appropriate. This improves the reliability of app state transitions and feature triggers.

Service startup logic:

• Updated the ServiceUtils.shouldRun logic so that the "Shut Up" feature can trigger the service independently of the usage access setting, ensuring it works even if usage access is not enabled.

Version update:

• Bumped versionCode to 48 and versionName to "15.4" in build.gradle.kts to reflect the new release.