Simplified the construction of a synchronizer.

There is no harm in letting the initializer hold a reference to the application context. So let it do that in order to simplify the construction of synchronizers.

src/androidTest/java/cash/z/wallet/sdk/util/DataDbScannerUtil.kt

@@ -78,7 +78,7 @@ class DataDbScannerUtil {
     @Test
     fun scanExistingDb() {
         initializer.open(birthday)
-        synchronizer = Synchronizer(context, initializer)
+        synchronizer = Synchronizer(initializer)
 
         println("sync!")
         synchronizer.start()

src/main/java/cash/z/wallet/sdk/Initializer.kt

@@ -22,7 +22,8 @@ import kotlin.reflect.KProperty
  * used before on this device.
  *
  * @param appContext the application context, used to extract the storage paths for the databases
- * and param files. A reference to the context is not held beyond initialization.
+ * and param files. A reference to the context is held beyond initialization in order to simplify
+ * synchronizer construction so that an initializer is all that is ever required.
  * @param host the host that the synchronizer should use.
  * @param port the port that the synchronizer should use when connecting to the host.
  * @param alias the alias to use for this synchronizer. Think of it as a unique name that allows
@@ -36,6 +37,8 @@ class Initializer(
     val port: Int = ZcashSdk.DEFAULT_LIGHTWALLETD_PORT,
     private val alias: String = ZcashSdk.DEFAULT_DB_NAME_PREFIX
 ) {
+    val context = appContext.applicationContext
+
     init {
         validateAlias(alias)
     }
@@ -44,17 +47,17 @@ class Initializer(
      * The path this initializer will use when checking for and downloading sapling params. This
      * value is derived from the appContext when this class is constructed.
      */
-    private val pathParams: String = "${appContext.cacheDir.absolutePath}/params"
+    private val pathParams: String = "${context.cacheDir.absolutePath}/params"
 
     /**
      * The path used for storing cached compact blocks for processing.
      */
-    private val pathCacheDb: String = cacheDbPath(appContext, alias)
+    private val pathCacheDb: String = cacheDbPath(context, alias)
 
     /**
      * The path used for storing the data derived from the cached compact blocks.
      */
-    private val pathDataDb: String = dataDbPath(appContext, alias)
+    private val pathDataDb: String = dataDbPath(context, alias)
 
     /**
      * A wrapped version of [cash.z.wallet.sdk.jni.RustBackendWelding] that will be passed to the

src/main/java/cash/z/wallet/sdk/SdkSynchronizer.kt

@@ -403,7 +403,7 @@ fun Synchronizer(
             initializer.import(seed, birthdayStore.getBirthday(), true, true)
         }
     }
-    return Synchronizer(appContext, initializer)
+    return Synchronizer(initializer)
 }
 
 /**
@@ -413,22 +413,17 @@ fun Synchronizer(
  * the wallet. From there, the initializer is passed to this function in order to start syncing from
  * where the wallet left off.
  *
- * @param appContext the application context. This is mostly used for finding databases and params
- * files within the apps secure storage area.
  * @param initializer the helper that is leveraged for creating all the components that the
  * Synchronizer requires. It is mainly responsible for initializing the databases associated with
  * this synchronizer.
  */
 @Suppress("FunctionName")
-fun Synchronizer(
-    appContext: Context,
-    initializer: Initializer
-): Synchronizer {
+fun Synchronizer(initializer: Initializer): Synchronizer {
     check(initializer.isInitialized) {
         "Error: RustBackend must be loaded before creating the Synchronizer. Verify that either" +
                 " the 'open', 'new' or 'import' function has been called on the Initializer."
     }
-    return Synchronizer(appContext, initializer.rustBackend, initializer.host, initializer.port)
+    return Synchronizer(initializer.context, initializer.rustBackend, initializer.host, initializer.port)
 }
 
 /**