VCN: Remove ArrayUtils hidden API usages

This patch removes two hidden API usages for moving
VCN to a mainline module. They are:
- ArrayUtils#convertToIntArray(List<Integer>)
- ArrayUtils#contains(int[], int)

Bug: 288465472
Test: atest FrameworksVcnTest && atest CtsVcnTestCases
Flag: EXEMPT pure refactoring
Change-Id: Iac10befda01c5ed52db85dfcd8ddc66b99782cac