add printError messages and tool exit to android device (#31400)

packages/flutter_tools/lib/src/android/android_device.dart

@@ -383,6 +383,10 @@ class AndroidDevice extends Device {
       // activity name from the .apk.
       package = await AndroidApk.fromAndroidProject(project.android);
     }
+    // There was a failure parsing the android project information.
+    if (package == null) {
+      throwToolExit('Problem building Android application: see above error(s).');
+    }
 
     printTrace("Stopping app '${package.name}' on $name.");
     await stopApp(package);

packages/flutter_tools/lib/src/application_package.dart

@@ -166,8 +166,11 @@ class AndroidApk extends ApplicationPackage {
 
     final File manifest = androidProject.appManifestFile;
 
-    if (!manifest.existsSync())
+    if (!manifest.existsSync()) {
+      printError('AndroidManifest.xml could not be found.');
+      printError('Please check ${manifest.path} for errors.');
       return null;
+    }
 
     final String manifestString = manifest.readAsStringSync();
     xml.XmlDocument document;
@@ -186,8 +189,11 @@ class AndroidApk extends ApplicationPackage {
     }
 
     final Iterable<xml.XmlElement> manifests = document.findElements('manifest');
-    if (manifests.isEmpty)
+    if (manifests.isEmpty) {
+      printError('AndroidManifest.xml has no manifest element.');
+      printError('Please check ${manifest.path} for errors.');
       return null;
+    }
     final String packageId = manifests.first.getAttribute('package');
 
     String launchActivity;
@@ -220,8 +226,11 @@ class AndroidApk extends ApplicationPackage {
       }
     }
 
-    if (packageId == null || launchActivity == null)
+    if (packageId == null || launchActivity == null) {
+      printError('package identifier or launch activity not found.');
+      printError('Please check ${manifest.path} for errors.');
       return null;
+    }
 
     return AndroidApk(
       id: packageId,