Export aom_codec_set_option from shared libraries

BUG=aomedia:2875,aomedia:2961

Change-Id: I0673f45b9d1949f3d7246cef2d629c65fc581009
(cherry picked from commit 31931b5b6410d0e6094721e49914ec2313ac2f57)

aom/exports_com

diff --git a/aom/exports_com b/aom/exports_com
index 6f796f5..266e294 100644
--- a/aom/exports_com
+++ b/aom/exports_com
@@ -6,6 +6,7 @@
 text aom_codec_error_detail
 text aom_codec_get_caps
 text aom_codec_iface_name
+text aom_codec_set_option
 text aom_codec_version
 text aom_codec_version_extra_str
 text aom_codec_version_str