Fix various lint warnings (#4409)

- Remove empty file `ExampleInstrumentedTest.java`.
- Replace deprecated `MigrationTestHelper` constructor call.
- Add reified inline extension methods for `Bundle` and `Intent` to
retrieve `Parcelable` and `Serializable` objects by calling the core
`BundleCompat` and `IntentCompat` methods, to allow shorter syntax and
removing the need to pass the class explicitly.
- Replace deprecated `drawable.setColorFilter()` with simpler
`drawable.setTint()` (uses blend mode `SRC_IN` by default, has the same
effect as `SRC_ATOP` when the source is a color).
- Rename shadowed variables (mostly caught exceptions).
- Remove unnecessary `.orEmpty()` on non-null fields.
- Replace `.size() == 0` with `.isEmpty()`.
- Prevent `NullPointerException` when `account.getDisplayName()` is
`null` in `StatusBaseViewHolder.setDisplayName()`.
- Declare `customEmojis` argument as non-null in
`StatusBaseViewHolder.setDisplayName()` because it calls
`CustomEmojiHelper.emojify()` which now requires it to be non-null.
- Prevent `NullPointerException` when no matching filter is found in
`StatusBaseViewHolder.setupFilterPlaceholder()`.
- Remove deprecated call to `setTargetFragment()` (target fragment is
not used anyway).
- Remove deprecated call to `isUserVisibleHint()` and test if the view
has been destroyed instead.
- Remove some unused imports.
- Remove unnecessary casts.
- Rename arguments to supertype names when a warning is shown.
- Prevent a potential memory leak by clearing the
`toolbarVisibilityDisposable` reference in `onDestroyView()`.

app/src/main/java/com/keylesspalace/tusky/util/ThemeUtils.kt

@@ -19,7 +19,6 @@ package com.keylesspalace.tusky.util
 import android.content.Context
 import android.content.res.Configuration
 import android.graphics.Color
-import android.graphics.PorterDuff
 import android.graphics.drawable.Drawable
 import androidx.annotation.AttrRes
 import androidx.appcompat.app.AppCompatDelegate
@@ -39,10 +38,7 @@ fun getDimension(context: Context, @AttrRes attribute: Int): Int {
 }
 
 fun setDrawableTint(context: Context, drawable: Drawable, @AttrRes attribute: Int) {
-    drawable.setColorFilter(
-        MaterialColors.getColor(context, attribute, Color.BLACK),
-        PorterDuff.Mode.SRC_IN
-    )
+    drawable.setTint(MaterialColors.getColor(context, attribute, Color.BLACK))
 }
 
 fun setAppNightMode(flavor: String?) {