defconfig: Enable OverlayFS for SM8150, sdmsteppe, trinket

OverlayFS is needed to be enabled to align with the
latest android base config. Enable it for SM8150,
sdmsteppe and trinket.

Change-Id: Idb9ed4f64b6f2bde455ac3795e76c3431c845062
Signed-off-by: Kaushal Kumar <kaushalk@codeaurora.org>