How to manage different support library versions for 3rd party deps with gradle?

This is certainly possible. In your projects build.gradle file (the top level build.gradle file) add the following code block:

ext {
    supportlib_version = '26.1.0'
    gps_version = '11.2.0'
}

//Ensure that all dependencies use the same version of the Android Support library
subprojects {
    project.configurations.all {
        resolutionStrategy.eachDependency { details ->
            if (details.requested.group == 'com.android.support'
                    && !details.requested.name.contains('multidex')) {
                details.useVersion "$supportlib_version"
            }
            if (details.requested.group == 'com.google.android.gms'
                    && !details.requested.name.contains('multidex')) {
                details.useVersion "$gps_version"
            }
        }
    }
}

The following code ensures that the 'com.android.support' dependency version will be equal to $supportlib_version for all dependencies. The same for the 'com.google.android.gms' framework.

Make sure that in your module's build.gradle file you also use these versions for your dependencies. E.g.:

compile "com.android.support:support-v4:$supportlib_version"

Read more about forcing a certain dependency version in the Official Gradle documentation.

Update Google has decoupled library versions. Therefore, forcing a specific version above 15.0.0 may not work. Instead, you can allow a limited range of versions. The example below allows any version higher than 15.0.0 but lower than 16.

gps_version = '[15.0.0, 16.0.0)'

First case: You have compatible libs wich already updated their own internal libs, No problem here.

Second case: You have libs in your project which have higher version than other libs contained internal to other libs, and these libs can be updated to new version with no such problem, Also No problem here.

Worst case: You have libs in your project which have higher version than other libs contained internal to other libs, and these libs doesn't have a new version that has already updated there internal libs, suggested solutions for that:

1. Download that library and include it to your app as project implementation project(':library') and update their internal libs.
2. OR Use other library instead.

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Don't forget to use ./gradlew app:dependencies to check your dependencies.

Also I believe should be there someway to do that automatically.