[Code health] Override clean Gradle task to remove generated ground-android/build

[gino-m]

The following root build.gradle stopped compiling after upgrading to Gradle 8.5:

task clean(type: Delete) {
    delete rootProject.buildDir
}

Alternate syntaxes were not accepted and not sure of the correct way to add it back. @shobhitagarwal1612 any ideas?

[shobhitagarwal1612]

We can probably remove this custom gradle task. I don't think this it's used very often.

[gino-m]

We can probably remove this custom gradle task. I don't this it's used very often.

That's what I ended up doing in #2181, but then after gradle clean the reports are left behind in /build dir.

[gino-m]

Unfortunately I still receive the following error when adding a module defined with a Kotlin Gradle build file in #2184:

Build file '/Users/gmiceli/Git/google/ground-android/shared/build.gradle.kts' line: 25

Failed to apply plugin class 'org.gradle.language.base.plugins.LifecycleBasePlugin'.
> Cannot add task 'clean' as a task with that name already exists.
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