I have already updated an app to playstore with below-mentioned uses-SDK:
<uses-sdk
android:maxSdkVersion="23"
android:minSdkVersion="17"
android:targetSdkVersion="23"/>
I want to downgrade my targetSdkVersion "23" to "22". I've done it. if I upload to playstore, will the update work for all the users properly?
You won't have any problem at all. What you are saying with your <uses-sdk> is that your app is fully tested to run in version 22 and can even run in lower versions until 17.
I suggest you to take a look to this documentation ver carefully.
android:targetSdkVersion
An integer designating the API Level that the application targets. If not set, the default value equals that given to minSdkVersion. This attribute informs the system that you have tested against the target version and the system should not enable any compatibility behaviors to maintain your app's forward-compatibility with the target version. The application is still able to run on older versions (down to minSdkVersion).
As Android evolves with each new version, some behaviors and even appearances might change. However, if the API level of the platform is higher than the version declared by your app's targetSdkVersion, the system may enable compatibility behaviors to ensure that your app continues to work the way you expect. You can disable such compatibility behaviors by specifying targetSdkVersion to match the API level of the platform on which it's running. For example, setting this value to "11" or higher allows the system to apply a new default theme (Holo) to your app when running on Android 3.0 or higher and also disables screen compatibility mode when running on larger screens (because support for API level 11 implicitly supports larger screens).
There are many compatibility behaviors that the system may enable based on the value you set for this attribute. Several of these behaviors are described by the corresponding platform versions in the Build.VERSION_CODES reference.
To maintain your application along with each Android release, you should increase the value of this attribute to match the latest API level, then thoroughly test your application on the corresponding platform version.
NO. You'll not be able to update your app by changing target SDK from 23 to 22.
PROBLEM
Users that have the APK with version code 6, which targets SDK 23 or higher, will receive an error when they attempt to upgrade to this APK because it targets SDK 22.
Now, as you all know, when we keep target SDK to <23, while installing the app by default all the permissions are granted for the app and if we keep target SDK 23 or higher, all the permissions are set to OFF while installing the app.
RESOLUTION
Ensure that your release including APKs targeting SDK 23 or higher to which all users that have the APK with version code 6 can upgrade.
If you didn't change the code(except the gradle file) and the app still works on the '23' version emulator then there shouldn't be any problem. It really depends on which features(classes and methods) you used in your code. If you didn't use any of Android 6's features in your code, then there shouldn't be any problem downgrading the target sdk version without having any change for android 6 users.
