LayoutLib: Fix System.arraycopy()

Framework has specialized versions of java.lang.System.arraycopy() for
all primitive data types. These versions are not present on the Desktop
VM. This change replaces calls to any of the specialized versions with
the more general alternative - the one using Objects.

Note that this was already being done for char.

Change-Id: If1584125fea8ecc080fb39a5ee6cdb4d922d0c98