PR Checklist

• The PR title follows our guidelines: https://github.com/NativeScript/NativeScript/blob/master/tools/notes/CONTRIBUTING.md#commit-messages.
• There is an issue for the bug/feature this PR is for. To avoid wasting your time, it's best to open a suggestion issue first and wait for approval before working on it.
• You have signed the CLA.
• All existing tests are passing: https://github.com/NativeScript/NativeScript/blob/master/tools/notes/DevelopmentWorkflow.md#running-unit-tests-application.
• Tests for the changes are included - https://github.com/NativeScript/NativeScript/blob/master/tools/notes/WritingUnitTests.md.

What is the current behavior?

Image provided source has its native instance disposed during view disposal even when ImageSource instance is provided by developer.

What is the new behavior?

Image provided source does not have its native instance disposed during view disposal when ImageSource instance is provided by developer.
To avoid this, we wrap the native source inside a new ImageSource instance.

Developers will be responsible for cleaning up the image sources they provide just like it has always been for android.
Also, improved code readability for ImageSource.setNativeSource.

Fixes #9820 (revisited) #10625