Fix/add namespace

[ahmedzayan7920]

Android Namespace Configuration Fix

Description

Added proper namespace configuration to support newer Android Gradle Plugin requirements.

Changes made:

• Removed package attribute from AndroidManifest.xml
• Added namespace declaration in build.gradle
• Maintained original package name (xyz.justsoft.video_thumbnail)

Why

This fix resolves build failures occurring with newer versions of the Android Gradle Plugin where namespace specification is required.

Testing Done

• Tested with latest Flutter version
• Verified build succeeds on Android
• Verified existing functionality continues to work

[AbnerBaluyut]

This should be merged ASAP!

[markesherriff]

This should be merged ASAP!

Agreed, I wanted to open a PR today, but see it's already here.

How do we get this moving?
I also see that 2 days ago there was a new version saying that the namespace was fixed. But it was not. This PR should do it.