Bump Robolectric to 4.8.1

1. Bump sdk to 32.
2. Remove icu4j from testImplementation because Robolectric has a higher
   icu4j dependency.

Signed-off-by: utzcoz <[email protected]>

Author: utzcoz

shell/platform/android/test/README.md

@@ -1,6 +1,6 @@
 # Unit testing Java code
 
-All Java code in the engine should now be able to be tested with Robolectric 4.7.3
+All Java code in the engine should now be able to be tested with Robolectric 4.8.1
 and JUnit 4. The test suite has been added after the bulk of the Java code was
 first written, so most of these classes do not have existing tests. Ideally code
 after this point should be tested, either with unit tests here or with

shell/platform/android/test_runner/build.gradle

@@ -69,8 +69,7 @@ android {
     implementation files(project.property("flutter_jar"))
     testImplementation "androidx.test:core:1.4.0"
     testImplementation "com.google.android.play:core:1.8.0"
-    testImplementation "com.ibm.icu:icu4j:69.1"
-    testImplementation "org.robolectric:robolectric:4.7.3"
+    testImplementation "org.robolectric:robolectric:4.8.1"
     testImplementation "junit:junit:4.13"
     testImplementation "androidx.test.ext:junit:1.1.3"
 

shell/platform/android/test_runner/src/main/resources/robolectric.properties

@@ -1,2 +1,2 @@
-sdk=31
+sdk=32
 shadows=io.flutter.CustomShadowContextImpl