Reserve space in super for dynamic partition metadata

The maximum size of all dynamic partition groups should not exceed
the super size - DAP metadata size. Today the configuration of
the device doesn't take the metadata into acount.

Since we recommend 4M to partners, reserve 4M here.

Bug: 182431975
Test: build
Change-Id: I2feb06531bf0bbbff8845fa485b5b4917152bad6
1 file changed