Remove unnecessary -keep rules for services (Kotlin#3263)

Fixes Kotlin#3111

ui/kotlinx-coroutines-android/resources/META-INF/com.android.tools/proguard/coroutines.pro

@@ -1,5 +1,6 @@
 # When editing this file, update the following files as well:
-# - META-INF/com.android.tools/r8-upto-1.6.0/coroutines.pro
+# - META-INF/com.android.tools/r8-upto-3.0.0/coroutines.pro
 # - META-INF/proguard/coroutines.pro
 
 -keep class kotlinx.coroutines.android.AndroidDispatcherFactory {*;}
+-keep class kotlinx.coroutines.android.AndroidExceptionPreHandler {*;}

ui/kotlinx-coroutines-android/resources/META-INF/com.android.tools/r8-from-1.6.0/coroutines.pro

@@ -9,8 +9,6 @@
     boolean ANDROID_DETECTED return true;
 }
 
--keep class kotlinx.coroutines.android.AndroidDispatcherFactory {*;}
-
 # Disable support for "Missing Main Dispatcher", since we always have Android main dispatcher
 -assumenosideeffects class kotlinx.coroutines.internal.MainDispatchersKt {
     boolean SUPPORT_MISSING return false;
@@ -21,4 +19,4 @@
     boolean getASSERTIONS_ENABLED() return false;
     boolean getDEBUG() return false;
     boolean getRECOVER_STACK_TRACES() return false;
-}
+}

ui/kotlinx-coroutines-android/resources/META-INF/com.android.tools/r8-upto-3.0.0/coroutines.pro

@@ -0,0 +1,10 @@
+# When editing this file, update the following files as well for AGP 3.6.0+:
+# - META-INF/com.android.tools/proguard/coroutines.pro
+# - META-INF/proguard/coroutines.pro
+
+# After R8 3.0.0 (or probably sometime before that), R8 learned how to optimize
+# classes mentioned in META-INF/services files, and explicitly -keeping them
+# disables these optimizations.
+# https://github.com/Kotlin/kotlinx.coroutines/issues/3111
+-keep class kotlinx.coroutines.android.AndroidDispatcherFactory {*;}
+-keep class kotlinx.coroutines.android.AndroidExceptionPreHandler {*;}

ui/kotlinx-coroutines-android/resources/META-INF/proguard/coroutines.pro

@@ -2,6 +2,7 @@
 
 # When editing this file, update the following files as well for AGP 3.6.0+:
 # - META-INF/com.android.tools/proguard/coroutines.pro
-# - META-INF/com.android.tools/r8-upto-1.6.0/coroutines.pro
+# - META-INF/com.android.tools/r8-upto-3.0.0/coroutines.pro
 
 -keep class kotlinx.coroutines.android.AndroidDispatcherFactory {*;}
+-keep class kotlinx.coroutines.android.AndroidExceptionPreHandler {*;}

ui/kotlinx-coroutines-android/src/AndroidExceptionPreHandler.kt

@@ -5,12 +5,10 @@
 package kotlinx.coroutines.android
 
 import android.os.*
-import androidx.annotation.*
 import kotlinx.coroutines.*
 import java.lang.reflect.*
 import kotlin.coroutines.*
 
-@Keep
 internal class AndroidExceptionPreHandler :
     AbstractCoroutineContextElement(CoroutineExceptionHandler), CoroutineExceptionHandler
 {