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}

webrtc/modules/audio_coding/codecs/isac/isac.gypi

@@ -9,7 +9,7 @@
 {
   'targets': [
     {
-      'target_name': 'iSAC',
+      'target_name': 'isac',
       'type': 'static_library',
       'dependencies': [
         '<(webrtc_root)/common_audio/common_audio.gyp:common_audio',

webrtc/modules/audio_coding/codecs/isac/isac_test.gypi

@@ -10,10 +10,10 @@
   'targets': [
     # simple kenny
     {
-      'target_name': 'iSACtest',
+      'target_name': 'isac_test',
       'type': 'executable',
       'dependencies': [
-        'iSAC',
+        'isac',
       ],
       'include_dirs': [
         './main/test',
@@ -28,10 +28,10 @@
     },
     # ReleaseTest-API
     {
-      'target_name': 'iSACAPITest',
+      'target_name': 'isac_api_test',
       'type': 'executable',
       'dependencies': [
-        'iSAC',
+        'isac',
       ],
       'include_dirs': [
         './main/test',
@@ -46,10 +46,10 @@
     },
     # SwitchingSampRate
     {
-      'target_name': 'iSACSwitchSampRateTest',
+      'target_name': 'isac_switch_samprate_test',
       'type': 'executable',
       'dependencies': [
-        'iSAC',
+        'isac',
       ],
       'include_dirs': [
         './main/test',
@@ -61,7 +61,7 @@
       'sources': [
         './main/test/SwitchingSampRate/SwitchingSampRate.cc',
         './main/util/utility.c',
-      ],    
+      ],
     },
 
   ],

webrtc/modules/audio_coding/codecs/isac/isacfix.gypi

@@ -9,7 +9,7 @@
 {
   'targets': [
     {
-      'target_name': 'iSACFix',
+      'target_name': 'isac_fix',
       'type': 'static_library',
       'dependencies': [
         '<(webrtc_root)/common_audio/common_audio.gyp:common_audio',

webrtc/modules/audio_coding/codecs/isac/isacfix_test.gypi

@@ -10,10 +10,10 @@
   'targets': [
     # kenny
     {
-      'target_name': 'iSACFixtest',
+      'target_name': 'isac_fix_test',
       'type': 'executable',
       'dependencies': [
-        'iSACFix',
+        'isac_fix',
         '<(webrtc_root)/test/test.gyp:test_support',
       ],
       'include_dirs': [