[shared_preferences] Fixes gradle version for shared preferences (macos, web) bug on android (#2470)

For some reason the version of gradle inside the android folders of the "sub packages" is different than the real one on the real shared_preferences plugin.

Even though my project only depends on the main package, I get an error when I try to run it:
diff --git a/packages/shared_preferences/shared_preferences_macos/CHANGELOG.md b/packages/shared_preferences/shared_preferences_macos/CHANGELOG.md
index 5a80c41..4b4954a 100644
--- a/packages/shared_preferences/shared_preferences_macos/CHANGELOG.md
+++ b/packages/shared_preferences/shared_preferences_macos/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 0.0.1+4
+
+* Bump gradle version to avoid bugs with android projects
+
 ## 0.0.1+3
 
 * Update README.
diff --git a/packages/shared_preferences/shared_preferences_macos/android/gradle/wrapper/gradle-wrapper.properties b/packages/shared_preferences/shared_preferences_macos/android/gradle/wrapper/gradle-wrapper.properties
index 019065d..caf54fa 100644
--- a/packages/shared_preferences/shared_preferences_macos/android/gradle/wrapper/gradle-wrapper.properties
+++ b/packages/shared_preferences/shared_preferences_macos/android/gradle/wrapper/gradle-wrapper.properties
@@ -2,4 +2,4 @@
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-4.10.2-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-5.1.1-all.zip
diff --git a/packages/shared_preferences/shared_preferences_macos/pubspec.yaml b/packages/shared_preferences/shared_preferences_macos/pubspec.yaml
index cddc201..a5bd95e 100644
--- a/packages/shared_preferences/shared_preferences_macos/pubspec.yaml
+++ b/packages/shared_preferences/shared_preferences_macos/pubspec.yaml
@@ -1,6 +1,6 @@
 name: shared_preferences_macos
 description: macOS implementation of the shared_preferences plugin.
-version: 0.0.1+3
+version: 0.0.1+4
 homepage: https://github.com/flutter/plugins/tree/master/packages/shared_preferences/shared_preferences_macos
 
 flutter:
diff --git a/packages/shared_preferences/shared_preferences_web/CHANGELOG.md b/packages/shared_preferences/shared_preferences_web/CHANGELOG.md
index 24ce6a3..120667e 100644
--- a/packages/shared_preferences/shared_preferences_web/CHANGELOG.md
+++ b/packages/shared_preferences/shared_preferences_web/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 0.1.2+3
+
+* Bump gradle version to avoid bugs with android projects
+
 # 0.1.2+2
 
 * Remove unused onMethodCall method.
diff --git a/packages/shared_preferences/shared_preferences_web/android/gradle/wrapper/gradle-wrapper.properties b/packages/shared_preferences/shared_preferences_web/android/gradle/wrapper/gradle-wrapper.properties
index 019065d..caf54fa 100644
--- a/packages/shared_preferences/shared_preferences_web/android/gradle/wrapper/gradle-wrapper.properties
+++ b/packages/shared_preferences/shared_preferences_web/android/gradle/wrapper/gradle-wrapper.properties
@@ -2,4 +2,4 @@
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-4.10.2-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-5.1.1-all.zip
diff --git a/packages/shared_preferences/shared_preferences_web/pubspec.yaml b/packages/shared_preferences/shared_preferences_web/pubspec.yaml
index 17a868e..2900014 100644
--- a/packages/shared_preferences/shared_preferences_web/pubspec.yaml
+++ b/packages/shared_preferences/shared_preferences_web/pubspec.yaml
@@ -1,7 +1,7 @@
 name: shared_preferences_web
 description: Web platform implementation of shared_preferences
 homepage: https://github.com/flutter/plugins/tree/master/packages/shared_preferences/shared_preferences_web
-version: 0.1.2+2
+version: 0.1.2+3
 
 flutter:
   plugin: