Embed proguard/R8 rules in kotlin-reflect artifact jar

The Android build pipeline can extract embedded proguard configurations
from dependencies and merge them automatically. This adds a conservative
proguard configuration to the kotlin-reflect JVM artifact in support of
that. This focuses mostly on just retaining what's necessary for
kotlin-reflect's own functionality to operate, but could be expanded if
community feedback discovers other good candidate rules.

With this in place - most Android projects using R8 or Proguard should
Just Work™️ with kotlin-reflect.

libraries/reflect/api/build.gradle

@@ -11,6 +11,9 @@ sourceSets {
         java {
             srcDir "${rootDir}/core/reflection.jvm/src"
         }
+        resources {
+            srcDir("${rootDir}/core/reflection.jvm/resources")
+        }
     }
 
     if (includeJava9) {