Use a bigger thread pool

This patch makes RiotX use an unbounded thread pool to handle
connections. The default thread pool for the android WorkManager has a
fairly anemic number of threads and I suspect this was causing
performance issues especially because of all the long-running jobs that
happen whenever you sync.

I tested this out on my phone and all of the sluggishness appears to
have gone away. I tested both the debug and release builds to make sure
it wasn't just some release optimization. RiotX is so much snappier now!

This fixes #1221

Signed-off-by: Waylon Cude <waylon.cude@finzdani.net>

matrix-sdk-android/src/main/java/im/vector/matrix/android/api/Matrix.kt

@@ -33,6 +33,7 @@ import im.vector.matrix.android.internal.util.BackgroundDetectionObserver
 import org.matrix.olm.OlmManager
 import java.io.InputStream
 import java.util.concurrent.atomic.AtomicBoolean
+import java.util.concurrent.Executors
 import javax.inject.Inject
 
 data class MatrixConfiguration(
@@ -61,7 +62,7 @@ class Matrix private constructor(context: Context, matrixConfiguration: MatrixCo
         Monarchy.init(context)
         DaggerMatrixComponent.factory().create(context, matrixConfiguration).inject(this)
         if (context.applicationContext !is Configuration.Provider) {
-            WorkManager.initialize(context, Configuration.Builder().build())
+            WorkManager.initialize(context, Configuration.Builder().setExecutor(Executors.newCachedThreadPool()).build())
         }
         ProcessLifecycleOwner.get().lifecycle.addObserver(backgroundDetectionObserver)
     }

vector/src/main/java/im/vector/riotx/VectorApplication.kt

@@ -56,6 +56,7 @@ import im.vector.riotx.features.version.VersionProvider
 import im.vector.riotx.push.fcm.FcmHelper
 import timber.log.Timber
 import java.text.SimpleDateFormat
+import java.util.concurrent.Executors
 import java.util.Date
 import java.util.Locale
 import javax.inject.Inject
@@ -146,7 +147,7 @@ class VectorApplication : Application(), HasVectorInjector, MatrixConfiguration.
 
     override fun providesMatrixConfiguration() = MatrixConfiguration(BuildConfig.FLAVOR_DESCRIPTION)
 
-    override fun getWorkManagerConfiguration() = androidx.work.Configuration.Builder().build()
+    override fun getWorkManagerConfiguration() = androidx.work.Configuration.Builder().setExecutor(Executors.newCachedThreadPool()).build()
 
     override fun injector(): VectorComponent {
         return vectorComponent