Prioritize @Serializable annotation on type usage over class usage

In `val p: @Serializable(X) Foo` and `@Serializable(Y) class Foo` situation,
now X would be chosen as serializer.

Fixes https://github.com/Kotlin/kotlinx.serialization/issues/1895

plugins/kotlinx-serialization/testData/boxIr/serializableOnPropertyType.kt

@@ -0,0 +1,56 @@
+// TARGET_BACKEND: JVM_IR
+
+// WITH_STDLIB
+
+import kotlinx.serialization.*
+import kotlinx.serialization.json.*
+import kotlinx.serialization.descriptors.*
+import kotlinx.serialization.encoding.*
+import kotlinx.serialization.internal.*
+
+
+@Serializable(BruhSerializerA::class)
+class Bruh(val s: String)
+
+object BruhSerializerA : KSerializer<Bruh> {
+    override val descriptor: SerialDescriptor
+        get() = PrimitiveSerialDescriptor("Bruh", PrimitiveKind.STRING)
+
+    override fun serialize(encoder: Encoder, value: Bruh) {
+        encoder.encodeString(value.s)
+    }
+
+    override fun deserialize(decoder: Decoder): Bruh {
+        return Bruh(decoder.decodeString())
+    }
+}
+
+object BruhSerializerB : KSerializer<Bruh> {
+    override val descriptor: SerialDescriptor
+        get() = PrimitiveSerialDescriptor("Bruh", PrimitiveKind.STRING)
+
+    override fun serialize(encoder: Encoder, value: Bruh) {
+        encoder.encodeString(value.s + "#")
+    }
+
+    override fun deserialize(decoder: Decoder): Bruh {
+        return Bruh(decoder.decodeString().removeSuffix("#"))
+    }
+}
+
+typealias BruhAlias = @Serializable(BruhSerializerB::class) Bruh
+
+@Serializable
+class Tester(
+    val b1: Bruh,
+    @Serializable(BruhSerializerB::class) val b2: Bruh,
+    val b3: @Serializable(BruhSerializerB::class) Bruh,
+    val b4: BruhAlias
+)
+
+fun box(): String {
+    val t = Tester(Bruh("a"), Bruh("b"), Bruh("c"), Bruh("d"))
+    val s = Json.encodeToString(t)
+    if (s != """{"b1":"a","b2":"b#","b3":"c#","b4":"d#"}""") return s
+    return "OK"
+}