Fix various lint warnings

[cbeyls]

• 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().