Fix UmAlQuraCalendar static data initilaization

Fix UmAlQuraCalendar static data initilaization

The current way of declaring the static data is cauing null reference exception
when the static constructor get called. the reason is the static initialization
method InitDateMapping is using the static array rawData which is not really
get initilaized yet when InitDateMapping execute.

The fix is moving rawData inside InitDateMapping.

https://github.com/dotnet/corefx/issues/6774#issuecomment-196044580

Commit migrated from https://github.com/dotnet/coreclr/commit/e305f4cd1dc28b38ffd25df2ac1492394602cf6b