Specify BOOT_KERNEL_MODULES

This is the first crack at the superset list of all possible boot
modules to load in first stage init from vendor_boot.  Anything else
not specified here is to be loaded in second stage init.  This is an
unabridged list of all the GKI and extra modules to start with,
except the dlkm set that Pixel normally load during second stage init.

This solves the regression that occurred when all modules landed on
vendor_boot, including the ones that were loaded later.

Signed-off-by: Mark Salyzyn <salyzyn@google.com>
Bug: 151950334
Bug: 156527199
Test: fastboot flashall & boot
Change-Id: I5ff54375a8c7242effb7cb2afbaabccf94ebda26