Move FLAC assets from extractor to testdata module

PiperOrigin-RevId: 293552271

library/extractor/build.gradle

@@ -33,6 +33,8 @@ android {
         }
     }
 
+    sourceSets.test.assets.srcDirs = ['src/test/assets/', '../../testdata/src/test/assets/']
+
     testOptions.unitTests.includeAndroidResources = true
 }
 
@@ -43,6 +45,7 @@ dependencies {
     implementation project(modulePrefix + 'library-common')
     testImplementation project(modulePrefix + 'library-core')
     testImplementation project(modulePrefix + 'testutils')
+    testImplementation project(modulePrefix + 'testdata')
     testImplementation 'org.robolectric:robolectric:' + robolectricVersion
 }