Update kotlinx-serialization to 1.6.3

And also add the JSON module, to be used by Room KMP soon.

Test: ./gradlew bOS
Change-Id: I78f33484ad5de46c1e8b38b2a73dc22e04d3da54
diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
index 4bf7b23..b9f36b0 100644
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -46,7 +46,7 @@
 kotlinNative = "1.9.22"
 kotlinCompileTesting = "1.4.9"
 kotlinCoroutines = "1.7.3"
-kotlinSerialization = "1.3.3"
+kotlinSerialization = "1.6.3"
 ksp = "1.9.22-1.0.17"
 ktfmt = "0.45"
 ktlint = "0.49.1"
@@ -185,6 +185,7 @@
 kotlinKlibCommonizer = { module = "org.jetbrains.kotlin:kotlin-klib-commonizer" }
 kotlinMetadataJvm = { module = "org.jetbrains.kotlinx:kotlinx-metadata-jvm", version = "0.9.0" }
 kotlinSerializationCore = { module = "org.jetbrains.kotlinx:kotlinx-serialization-core", version.ref = "kotlinSerialization" }
+kotlinSerializationJson = { module = "org.jetbrains.kotlinx:kotlinx-serialization-json", version.ref = "kotlinSerialization" }
 kotlinSerializationProtobuf = { module = "org.jetbrains.kotlinx:kotlinx-serialization-protobuf", version.ref = "kotlinSerialization" }
 kotlinGradlePluginz = { module = "org.jetbrains.kotlin:kotlin-gradle-plugin", version.ref = "kotlin" }
 kotlinStdlib = { module = "org.jetbrains.kotlin:kotlin-stdlib" }