Rename targets to use lower case format.

It makes writing a build script for merging libraries
across architectures easier. See talk/build/build_ios_libs.sh.

BUG=
R=andrew@webrtc.org, kjellander@webrtc.org

Review URL: https://codereview.webrtc.org/1171793002.

Cr-Commit-Position: refs/heads/master@{#9412}
diff --git a/webrtc/modules/audio_coding/audio_coding_tests.gypi b/webrtc/modules/audio_coding/audio_coding_tests.gypi
index 86a92c5..84ef867 100644
--- a/webrtc/modules/audio_coding/audio_coding_tests.gypi
+++ b/webrtc/modules/audio_coding/audio_coding_tests.gypi
@@ -18,7 +18,7 @@
       'type': '<(gtest_target_type)',
       'dependencies': [
         'audio_processing',
-        'iSACFix',
+        'isac_fix',
         'webrtc_opus',
         '<(DEPTH)/testing/gtest.gyp:gtest',
         '<(webrtc_root)/system_wrappers/system_wrappers.gyp:system_wrappers',