Fix android lint errors

Author: niranjan94

app/src/main/kotlin/com/njlabs/showjava/MainApplication.kt

@@ -26,7 +26,6 @@ import androidx.appcompat.app.AppCompatDelegate
 import androidx.multidex.MultiDexApplication
 import androidx.preference.PreferenceManager
 import androidx.work.WorkManager
-import com.google.android.gms.ads.MobileAds
 import com.njlabs.showjava.utils.Ads
 import com.njlabs.showjava.utils.UserPreferences
 import com.njlabs.showjava.utils.logging.ProductionTree

app/src/main/kotlin/com/njlabs/showjava/activities/apps/AppsActivity.kt

@@ -36,7 +36,6 @@ import com.njlabs.showjava.activities.apps.adapters.AppsListAdapter
 import com.njlabs.showjava.activities.decompiler.DecompilerActivity
 import com.njlabs.showjava.data.PackageInfo
 import io.reactivex.android.schedulers.AndroidSchedulers
-import io.reactivex.disposables.Disposable
 import io.reactivex.schedulers.Schedulers
 import kotlinx.android.synthetic.main.activity_apps.*
 import timber.log.Timber

app/src/main/kotlin/com/njlabs/showjava/activities/landing/LandingHandler.kt

@@ -23,7 +23,6 @@ import androidx.work.WorkManager
 import com.njlabs.showjava.data.SourceInfo
 import com.njlabs.showjava.utils.appStorage
 import io.reactivex.Observable
-import org.apache.commons.io.FileUtils
 import timber.log.Timber
 import java.io.File
 import java.io.IOException

app/src/main/kotlin/com/njlabs/showjava/activities/settings/SettingsActivity.kt

@@ -29,15 +29,13 @@ import androidx.appcompat.app.AlertDialog
 import androidx.appcompat.app.AppCompatDelegate
 import androidx.preference.Preference
 import androidx.preference.PreferenceFragmentCompat
-import com.google.common.base.CaseFormat
 import com.njlabs.showjava.R
 import com.njlabs.showjava.activities.BaseActivity
 import com.njlabs.showjava.utils.Ads
 import com.njlabs.showjava.utils.UserPreferences
 import io.reactivex.android.schedulers.AndroidSchedulers
 import io.reactivex.disposables.Disposable
 import io.reactivex.schedulers.Schedulers
-import timber.log.Timber
 
 
 class SettingsActivity : BaseActivity() {
@@ -111,7 +109,7 @@ class SettingsActivity : BaseActivity() {
 
                 Toast.makeText(context, R.string.themeChangeCloseInfo, Toast.LENGTH_SHORT).show()
 
-                activity?.let {
+                activity.let {
                     it.startActivity(Intent(it, SettingsActivity::class.java))
                     it.finish()
                 }

app/src/main/kotlin/com/njlabs/showjava/decompilers/BaseDecompiler.kt

@@ -71,6 +71,7 @@ abstract class BaseDecompiler(val context: Context, val data: Data) {
     private var onLowMemory: ((Boolean) -> Unit)? = null
 
     init {
+        @Suppress("LeakingThis")
         printStream = PrintStream(ProgressStream(this))
         System.setErr(printStream)
         System.setOut(printStream)

app/src/main/kotlin/com/njlabs/showjava/receivers/DecompilerActionReceiver.kt

@@ -21,9 +21,7 @@ package com.njlabs.showjava.receivers
 import android.content.BroadcastReceiver
 import android.content.Context
 import android.content.Intent
-import androidx.work.WorkManager
 import com.njlabs.showjava.Constants
-import com.njlabs.showjava.utils.ProcessNotifier
 import com.njlabs.showjava.workers.DecompilerWorker
 import timber.log.Timber
 

app/src/main/kotlin/com/njlabs/showjava/utils/ExceptionHandler.kt

@@ -19,7 +19,6 @@
 package com.njlabs.showjava.utils
 
 
-import android.os.Environment
 import timber.log.Timber
 import java.io.*
 import java.util.zip.ZipEntry

app/src/main/kotlin/com/njlabs/showjava/utils/ZipUtils.kt

@@ -20,7 +20,6 @@ package com.njlabs.showjava.utils.secure
 
 import android.annotation.SuppressLint
 import android.content.Context
-import android.content.pm.ApplicationInfo
 import android.content.pm.PackageManager
 import android.util.Base64
 import com.android.volley.Response