ANDROID: GKI: Header generation fix and improvements

Remove dependency on kleaf intermediate abi_symbollist.raw
and use vendor symbol lists as dependencies for header
generation targets. This prevents the feature to break in
case kleaf path and/or sandboxes changes and rebuilds the
header files if any vendor symbol list changes.

Update the header generation script to process the symbol lists
before generating headers to make sure symbols are in byte order,
any symbol list marker, whitespaces and emptylines are removed
for kernel binary search API.

Bug: 232430739
Test: TH
Change-Id: Ib5783fb21543844dac7faf1fb0fcf3e7bd2bf608
Signed-off-by: Ramji Jiyani <ramjiyani@google.com>
(cherry picked from commit 1da1154eda5c026858a1e651c9aecb883d1305b3)