Migrate to the Android embedding v2

[aman-singh7]

Fixes #200

Describe the changes you have made in this PR -

Screenshots of the changes (If any) -

Note: Please check Allow edits from maintainers. if you would like us to assist in the PR.

[coveralls]

Pull Request Test Coverage Report for Build 1831582213

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 88 unchanged lines in 2 files lost coverage.
• Overall coverage decreased (-1.2%) to 70.74%

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Files with Coverage Reduction	New Missed Lines	%
lib/data/restriction_elements.dart	8	0%
lib/utils/unicode_map.dart	80	0%

Totals
Change from base Build 1776677457:	-1.2%
Covered Lines:	3861
Relevant Lines:	5458

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💛 - Coveralls

[Nitish145]

@aman-singh7 Can you break this PR into two of which the first handle the flutter 2.10.0's Looking up a deactivated widget's ancestor is unsafe error for photo_view. Then this one actually is Migrating to Android embedding v2.

[aman-singh7]

ok @Nitish145 👍

[aman-singh7]

@Nitish145 Done. Tests will pass only when both of them are merged. 😅

[Nitish145]

@aman-singh7 Please rebase this PR, so that only Android embedding v2 changes are the ones that build this PR.