Unable to get provider com.crashlytics.android.CrashlyticsInitProvider

I found that the only thing you need to do after following the instruction on the Firebase Crashlytics docs is to apply the fabric plugin in your app build file (This step is actually missing from the docs!).

In your app-level build.gradle add the following

// Apply the Fabric plugin
apply plugin: 'io.fabric'

Edit: It appears that this step has been recently added to the docs (See Step 2 / part 2).

If you are going to use other Firebase's API's, I'd suggest to setup crashlytics
As mentioned on Firebase's crashlytics page, here.

And obviously before that you'd need to setup firebase for your app
and create project through firebase console.
I believe you had already done that.

It's because I see small difference in crashlytics setup on these two pages(fabric and firebase).
like on firebase's crashlytics:
in app level gradle

dependencies {
    // ...
    implementation 'com.crashlytics.sdk.android:crashlytics:2.9.3'
}

on fabric:

dependencies {
    // ...
      implementation('com.crashlytics.sdk.android:crashlytics:2.9.4@aar') {
    transitive = true;
  }
}

You won't need to add fabric api key through manifest if you are using with firebase, I think it somehow get connected with firebase key(just guessing).
I'm saying this from my experience, anyone correct me if I'm somewhere wrong.

This helped to solve my problem

<meta-data
            android:name="firebase_crashlytics_collection_enabled"
            android:value="false" />

And remove this:

<meta-data android:name="firebase_crash_collection_enabled" android:value="false" />