Revert all src AndroidX changes for 1.0.0 plugins

The AndroidX migration didn't increment the major version for plugins >=
1.0.0. This commit reverts the code changes in the affected plugins.

Author: Michael Klimushyn

packages/firebase_analytics/android/build.gradle

@@ -8,7 +8,7 @@ buildscript {
     }
 
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.3.0'
+        classpath 'com.android.tools.build:gradle:3.2.1'
     }
 }
 
@@ -22,11 +22,11 @@ rootProject.allprojects {
 apply plugin: 'com.android.library'
 
 android {
-    compileSdkVersion 28
+    compileSdkVersion 27
 
     defaultConfig {
         minSdkVersion 16
-        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
+        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
     }
     lintOptions {
         disable 'InvalidPackage'

packages/firebase_analytics/example/android/app/build.gradle

@@ -25,7 +25,7 @@ apply plugin: 'com.android.application'
 apply from: "$flutterRoot/packages/flutter_tools/gradle/flutter.gradle"
 
 android {
-    compileSdkVersion 28
+    compileSdkVersion 27
 
     lintOptions {
         disable 'InvalidPackage'
@@ -34,10 +34,10 @@ android {
     defaultConfig {
         applicationId "io.flutter.plugins.firebaseanalyticsexample"
         minSdkVersion 16
-        targetSdkVersion 28
+        targetSdkVersion 27
         versionCode flutterVersionCode.toInteger()
         versionName flutterVersionName
-        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
+        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
     }
 
     buildTypes {

packages/firebase_analytics/example/android/app/gradle.properties

@@ -6,7 +6,7 @@ buildscript {
     }
 
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.3.0'
+        classpath 'com.android.tools.build:gradle:3.2.1'
         classpath 'com.google.gms:google-services:4.2.0'
     }
 }

packages/firebase_analytics/example/android/app/gradle/wrapper/gradle-wrapper.properties

@@ -8,7 +8,7 @@ buildscript {
     }
 
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.3.0'
+        classpath 'com.android.tools.build:gradle:3.2.1'
     }
 }
 
@@ -22,11 +22,11 @@ rootProject.allprojects {
 apply plugin: 'com.android.library'
 
 android {
-    compileSdkVersion 28
+    compileSdkVersion 27
 
     defaultConfig {
         minSdkVersion 16
-        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
+        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
     }
     lintOptions {
         disable 'InvalidPackage'

packages/firebase_analytics/example/android/build.gradle

@@ -25,7 +25,7 @@ apply plugin: 'com.android.application'
 apply from: "$flutterRoot/packages/flutter_tools/gradle/flutter.gradle"
 
 android {
-    compileSdkVersion 28
+    compileSdkVersion 27
 
     lintOptions {
         disable 'InvalidPackage'
@@ -34,10 +34,10 @@ android {
     defaultConfig {
         applicationId 'io.flutter.plugins.firebasedatabaseexample'
         minSdkVersion 16
-        targetSdkVersion 28
+        targetSdkVersion 27
         versionCode flutterVersionCode.toInteger()
         versionName flutterVersionName
-        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
+        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
     }
 
     buildTypes {
@@ -55,8 +55,8 @@ flutter {
 
 dependencies {
     testImplementation 'junit:junit:4.12'
-    androidTestImplementation 'androidx.test:runner:1.1.1'
-    androidTestImplementation 'androidx.test.espresso:espresso-core:3.1.1'
+    androidTestImplementation 'com.android.support.test:runner:1.0.2'
+    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
 }
 
 apply plugin: 'com.google.gms.google-services'

packages/firebase_database/android/build.gradle

@@ -5,7 +5,7 @@ buildscript {
     }
 
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.3.0'
+        classpath 'com.android.tools.build:gradle:3.2.1'
         classpath 'com.google.gms:google-services:4.2.0'
     }
 }