Change the example to use AOM encoder, the rav1e binary consume too much of bandwith for Git LFS

Author: dreampiggy

Example/Podfile

@@ -3,7 +3,7 @@
 target 'SDWebImageAVIFCoder_Example' do
   platform :ios, '8.0'
   pod 'SDWebImageAVIFCoder', :path => '../'
-  pod 'libavif', :subspecs => ['librav1e', 'libdav1d']
+  pod 'libavif', :subspecs => ['libaom', 'libdav1d']
 
   target 'SDWebImageAVIFCoder_Tests' do
     inherit! :search_paths
@@ -15,11 +15,11 @@ end
 target 'SDWebImageAVIFCoder_Example macOS' do
   platform :osx, '10.10'
   pod 'SDWebImageAVIFCoder', :path => '../'
-  pod 'libavif', :subspecs => ['librav1e', 'libdav1d']
+  pod 'libavif', :subspecs => ['libaom', 'libdav1d']
 end
 
 target 'SDWebImageAVIFCoder_Example CLI' do
   platform :osx, '10.10'
   pod 'SDWebImageAVIFCoder', :path => '../'
-  pod 'libavif', :subspecs => ['librav1e', 'libdav1d']
+  pod 'libavif', :subspecs => ['libaom', 'libdav1d']
 end