update the 4.14 and 4.19 prebuilt kernels am: 28cf7f4459 am: d159aa39f5 am: 32dbfb3e9c am: eb6c0cf05c am: 196ac7beb5

Original change: https://android-review.googlesource.com/c/device/ti/beagle-x15-kernel/+/1512662

Change-Id: I30caa561db881d388e1a797af80bf06131d1297a