chore: bump snapshot version to 0.28.3-SNAPSHOT

Author: aws-sdk-kotlin-ci

gradle.properties

@@ -8,7 +8,7 @@ kotlin.native.ignoreDisabledTargets=true
 org.gradle.jvmargs=-Xmx2G -XX:MaxMetaspaceSize=1G
 
 # SDK
-sdkVersion=0.28.2
+sdkVersion=0.28.3-SNAPSHOT
 
 # codegen
 codegenVersion=0.28.2