Drawing manager Customizations

[shubham1g5]

• Abstracts and Exposes getCurrentPolygon to get polygon from drawn circles
• Adds a function resetDrawing to reset the DrawingManager to it's initial stage.

[coveralls]

Pull Request Test Coverage Report for Build 1618

• 4 of 7 (57.14%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-0.002%) to 52.721%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
library/src/main/java/io/ona/kujaku/manager/DrawingManager.java	4	7	57.14%
<!--	Total:	4	7	57.14%	-->

Totals
Change from base Build 1616:	-0.002%
Covered Lines:	3061
Relevant Lines:	5806

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💛 - Coveralls

[shubham1g5]

@ekigamba Look like both comments on this resolved now, Is there anything pending on my end for this PR ?