[INTERNAL] sap.m.DatePicker: QUnit.skip removal
[INTERNAL] sap.m.DatePicker: QUnit.skip removal

The tests were failing inconsistently before and since once that caused
the voter to be unstable, skip was introduced.
Now after another test on different browsers, the tests are green
everytime so "skip" is changed with "test".

Change-Id: Ib58e813308aa1678017a2149b58a91c4b76b8c32
BCP: 1970304700

SAP/openui5,SAP/openui5,SAP/openui5,SAP/openui5