Remove keep rules mentioning kotlinx.coroutines.android from core module (#2061)

The rule -keepnames class kotlinx.coroutines.android.AndroidDispatcherFactory {} is present in kotlinx.coroutines.android/META-INF/proguard/coroutines.pro and should therefore is not needed.

Author: mkj-gram

kotlinx-coroutines-core/jvm/resources/META-INF/proguard/coroutines.pro

@@ -1,8 +1,6 @@
 # ServiceLoader support
 -keepnames class kotlinx.coroutines.internal.MainDispatcherFactory {}
 -keepnames class kotlinx.coroutines.CoroutineExceptionHandler {}
--keepnames class kotlinx.coroutines.android.AndroidExceptionPreHandler {}
--keepnames class kotlinx.coroutines.android.AndroidDispatcherFactory {}
 
 # Most of volatile fields are updated with AFU and should not be mangled
 -keepclassmembernames class kotlinx.** {
@@ -12,4 +10,5 @@
 # Same story for the standard library's SafeContinuation that also uses AtomicReferenceFieldUpdater
 -keepclassmembernames class kotlin.coroutines.SafeContinuation {
     volatile <fields>;
-}
+}
+