[google_maps_flutter] fix to properly place polyline at initial camera position in example app

[klaes-ashford]

Description

since in the code _polylineIdCounter is used to offset the latitude and it being 2 for initial polyline, goes out of the map viewport and when ever you add a polyline it is not visible at first. you have to pan around to see the initially added polyline. This at first gives a false impression that the polyline is not working. this change when merged will fix that issue.

Related Issues

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[klaes-ashford]

@cyanglaz this being a small fix in example app, I am not sure if I should add a changelog since none of the api's is being touched.

[cyanglaz]

Thank you for sending this PR. Yes, we need to update the CHANGLOG and version for a fix in the example app. Could you explain more in detail what are you trying to fix here? Is there an issue that you can link this to?

[klaes-ashford]

as you can see in the gif, initially, you can not see the polyline at first when you click the add button. you have to pan around to see the polyline. this might confuse a naive user (it occured to me :P), so I thought, it would be great to see the initial polyline at first time itself.

@cyanglaz with a slight modification to the initialCameraPosition latitude we can place the initial polyline to the center of view port.

[cyanglaz]

@aswinkviswanath I see thanks for the fix! Please update the changelog and version. I will land this!

[klaes-ashford]

@cyanglaz CHANGELOG and version updated.

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[cyanglaz]

@klaes-ashford The PR is almost ready to merge, it looks like you have to sign the CLA.

[klaes-ashford]

@cyanglaz Sorry, but I used the wrong email address in PR, and I don't have access to the same.

[klaes-ashford]

@cyanglaz please see #2941. These changes have been moved there.