perf: android proguard rules

Signed-off-by: Kraity <kraity@krait.cn>
(cherry picked from commit 1fccc2b)

core/src/main/resources/META-INF/proguard/fastjson2.pro

@@ -0,0 +1,26 @@
+-keep, allowoptimization, allowobfuscation
+  @com.alibaba.fastjson2.annotation.JSONType class *
+# Keep the fields and methods with @JSONField
+-keepclassmembers, allowobfuscation class * {
+  @com.alibaba.fastjson2.annotation.JSONField <fields>;
+  @com.alibaba.fastjson2.annotation.JSONField <methods>;
+}
+
+# Ignore warning
+-dontwarn java.beans.Transient
+-dontwarn com.alibaba.fastjson.*
+
+# Keep the fields and methods annotated with
+# @JSONField for classes which are referenced
+-if class * {
+  @com.alibaba.fastjson2.annotation.JSONField <fields>;
+}
+-keep, allowobfuscation, allowoptimization class <1>
+-if class * {
+  @com.alibaba.fastjson2.annotation.JSONField <methods>;
+}
+-keep, allowobfuscation, allowoptimization class <1>
+
+# Keep any (anonymous) classes extending TypeReference
+-keep, allowobfuscation class com.alibaba.fastjson2.TypeReference
+-keep, allowobfuscation class * extends com.alibaba.fastjson2.TypeReference