Repository: flutter
Issue: Category and action in AndroidManifest.xml are ignored.
Labels: platform-android,has reproducible steps,P2,found in release: 2.5,found in release: 2.6,team-android,triaged-android

It seems that the intent-filter of the following MainActivity in AndroidManifest.xml is being ignored. 
```
            <intent-filter>
                <action android:name="android.intent.action.MAIN"/>
                <category android:name="android.intent.category.LAUNCHER"/>
            </intent-filter>
```
Please fix it so that it is not ignored.

### Reproduction Procedure
1. Create a project with the following command.
`flutter create helloworld`
1. Confirm that the following intent-filter is listed in MainActivity of android/app/src/main/AndroidManifest.xml.
```
            <intent-filter>
                <action android:name="android.intent.action.MAIN"/>
                <category android:name="android.intent.category.LAUNCHER"/>
            </intent-filter>
```
~~2. Debug execution on android~~

3. `flutter run`
1. Select an android device
1. Use the following command to check the activity.
`adb shell dumpsys activity activities`
4. Make sure that `android.intent.action.MAIN` and `android.intent.category.LAUNCHER` are not set in MainActivity as shown below
```
      * Hist #0: ActivityRecord{c44c2c1 u0 com.example.helloworld/.MainActivity t16425}
          packageName=com.example.helloworld processName=com.example.helloworld
          launchedFromUid=2000 launchedFromPackage=com.android.shell launchedFromFeature=null userId=0
          app=ProcessRecord{7eb7d23 9537:com.example.helloworld/u0a473}
          Intent { act=android.intent.action.RUN flg=0x30000000 cmp=com.example.helloworld/.MainActivity (has extras) }
          rootOfTask=true task=Task{304f38b #16425 type=standard A=10473:com.example.helloworld U=0 visible=true mode=fullscreen translucent=false sz=1}
          taskAffinity=10473:com.example.helloworld
          mActivityComponent=com.example.helloworld/.MainActivity
          baseDir=/data/app/~~f8t9xOH_Gd3N-hpwrjV-Qg==/com.example.helloworld-Zn9Cfkbp_9ScCmGy3nq_tQ==/base.apk
          dataDir=/data/user/0/com.example.helloworld
          stateNotNeeded=false componentSpecified=false mActivityType=standard
          compat={440dpi} labelRes=0x0 icon=0x7f080000 theme=0x7f0a0000
```


On the other hand, if we build with Android studio, `android.intent.action.MAIN` and `android.intent.category.LAUNCHER` will be set as shown below
```
      * Hist #0: ActivityRecord{dce55fe u0 com.example.helloworld/.MainActivity t16429}
          packageName=com.example.helloworld processName=com.example.helloworld
          launchedFromUid=2000 launchedFromPackage=com.android.shell launchedFromFeature=null userId=0
          app=ProcessRecord{5b5d40a 3116:com.example.helloworld/u0a473}
          Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x10000000 cmp=com.example.helloworld/.MainActivity }
          rootOfTask=true task=Task{fe526d6 #16429 type=standard A=10473:com.example.helloworld U=0 visible=true mode=fullscreen translucent=false sz=1}
          taskAffinity=10473:com.example.helloworld
          mActivityComponent=com.example.helloworld/.MainActivity
          baseDir=/data/app/~~a5XCSYYuQevomyyuDgCICQ==/com.example.helloworld-yrUT5s1dBP3can43vLQD1g==/base.apk
          dataDir=/data/user/0/com.example.helloworld
          stateNotNeeded=false componentSpecified=false mActivityType=standard
          compat={440dpi} labelRes=0x0 icon=0x7f080000 theme=0x7f0a0000
```

<details>
<summary>flutter doctor -v</summary>

```
[✓] Flutter (Channel stable, 2.5.2, on macOS 11.6.1 20G224 darwin-x64, locale ja-JP)
    • Flutter version 2.5.2 at /Users/kiyokazu.hino/development/flutter
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision 3595343e20 (9 weeks ago), 2021-09-30 12:58:18 -0700
    • Engine revision 6ac856380f
    • Dart version 2.14.3

[✓] Android toolchain - develop for Android devices (Android SDK version 30.0.3)
    • Android SDK at /Users/kiyokazu.hino/Library/Android/sdk
    • Platform android-31, build-tools 30.0.3
    • Java binary at: /Applications/Android Studio.app/Contents/jre/Contents/Home/bin/java
    • Java version OpenJDK Runtime Environment (build 11.0.10+0-b96-7281165)
    • All Android licenses accepted.

[✓] Xcode - develop for iOS and macOS
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • Xcode 13.0, Build version 13A233
    • CocoaPods version 1.10.2

[✓] Chrome - develop for the web
    • Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome

[✓] Android Studio (version 2020.3)
    • Android Studio at /Applications/Android Studio.app/Contents
    • Flutter plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/9212-flutter
    • Dart plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/6351-dart
    • Java version OpenJDK Runtime Environment (build 11.0.10+0-b96-7281165)

[✓] VS Code (version 1.62.3)
    • VS Code at /Applications/Visual Studio Code.app/Contents
    • Flutter extension version 3.29.0

[✓] Connected device (2 available)
    • Pixel 5 (mobile) • 12271FDD4000K4 • android-arm64  • Android 12 (API 31)
    • Chrome (web)     • chrome         • web-javascript • Google Chrome 96.0.4664.55
```
</details>