Adding unit tests for ConcurrentHashMap

Adding tests to cover the following APIs:

java.util.concurrent.ConcurrentHashMap.newKeySet(int)
java.util.concurrent.ConcurrentHashMap.reduceEntries(long, java.util.function.Function, java.util.function.BiFunction)
java.util.concurrent.ConcurrentHashMap.reduceEntriesToDouble(long, java.util.function.ToDoubleFunction, double, java.util.function.DoubleBinaryOperator)
java.util.concurrent.ConcurrentHashMap.reduceEntriesToInt(long, java.util.function.ToIntFunction, int, java.util.function.IntBinaryOperator)
java.util.concurrent.ConcurrentHashMap.reduceEntriesToLong(long, java.util.function.ToLongFunction, long, java.util.function.LongBinaryOperator)
java.util.concurrent.ConcurrentHashMap.reduceToDouble(long, java.util.function.ToDoubleBiFunction, double, java.util.function.DoubleBinaryOperator)
java.util.concurrent.ConcurrentHashMap.reduceToInt(long, java.util.function.ToIntBiFunction, int, java.util.function.IntBinaryOperator)
java.util.concurrent.ConcurrentHashMap.reduceToLong(long, java.util.function.ToLongBiFunction, long, java.util.function.LongBinaryOperator)

Change-Id: Ic2a58cae5c56d3197445872aad1e7c30e20ba0df
Bug: 182165523
Test: atest CtsLibcoreOjTestCases:ConcurrentHashMap8Test
1 file changed