build_rootfs.sh: Enable TRIM on root

In practice our images will usually be run on virtual devices on top of
virtio_blk, which supports discard/TRIM, but for the sole physical
device we support (RockPi 4B) it is *essential* to enable this for
performance and NAND longevity reasons. So, just enable it globally.

Bug: 198839386
Change-Id: I11152012f6df6dd9ebbb566b75fd464797465027
1 file changed
tree: 113b649613a048011cb84e4c820bb20ca9e7177a
  1. devicetree/
  2. net/
  3. Android.bp
  4. METADATA