AOSP: Add "libc" to soong static_executable targets.

AOSP: Add "libc" to soong static_executable targets.

When building a static exectuable for "arm", the libgcc is automatically
included by the build system *after* libc, but libgcc has some symbol
dependencies on "libc", like for example the "raise" symbol.

libgcc, libatomic and libcompiler_rt-extras are passed in a group
(enclosed by --start-group and --end-group) so they all are included
regardless of the order inside that group. Nevertheless libc only
appears outside this group and before them, so the undefined references
from libgcc are not resolved.

This patch adds "libc" as a explicit static_libs dependency to
static_executable targets forcing it to be included in the group.

Bug: 34220783
Test: mmma external/e2fsprogs
Change-Id: Ia18db10da0f18494600d7e0c870291902d71b287
From AOSP commit: b799ad178fa18c2925a283206496d3f5d6e87f35

Signed-off-by: Theodore Ts'o <tytso@mit.edu>