Add --include_build_info flag to apexer invocation.

Bug: 144477678
Test: verified that apex_build_info.pb is populated and included in the
final apex.
Change-Id: Iecbc2a68a82595eee32aaa26d11a7253daf89f69

apex/builder.go

@@ -105,6 +105,7 @@ var (
 			`${apexer} --force --manifest ${manifest} ` +
 			`--file_contexts ${file_contexts} ` +
 			`--canned_fs_config ${canned_fs_config} ` +
+			`--include_build_info ` +
 			`--payload_type image ` +
 			`--key ${key} ${opt_flags} ${image_dir} ${out} `,
 		CommandDeps: []string{"${apexer}", "${avbtool}", "${e2fsdroid}", "${merge_zips}",