ANDROID: KMI symbol lists: migrate section name

Libabigail learned to accept 'symbol_list' as a valid suffix for symbol
list sections. Hence make use of it consistently.

Bug: 162536543
Signed-off-by: Matthias Maennich <maennich@google.com>
Change-Id: I1454b0068769c9e57a533dafb6267e63adb7ceb0