Generated proguard rules are missing from output

[wynneplaga]

First noted here: #991 (comment)

Proguard rules generated by Moshi do not end up in the output. This prevents using moshi-kotlin-codegen as a drop-in library.

Substitute manual proguard rules for anyone facing this issue:

-keepnames @com.squareup.moshi.JsonClass class *
-keep class * extends com.squareup.moshi.JsonAdapter {
    public <init>(com.squareup.moshi.Moshi);
}
-if @com.squareup.moshi.JsonClass class *
-keepnames class kotlin.jvm.internal.DefaultConstructorMarker
-keepclassmembers @com.squareup.moshi.JsonClass @kotlin.Metadata class * {
    synthetic <init>(...);
}