Add Accounts DynamoDB

* Add additional test cases to AccountsTest
* Migrate AccountsManagerTest to JUnit 5
* Add AccountsDynamoDbConfiguration
* Add Account.dynamoDbMigrationversion
* Add DynamicAccountsDynamoDbMigrationConfiguration
* Add AccountsDynamoDb to AccountsManager
* Add AccountsDynamoDbMigrator

service/src/main/java/org/whispersystems/textsecuregcm/configuration/AccountsDynamoDbConfiguration.java

@@ -0,0 +1,13 @@
+package org.whispersystems.textsecuregcm.configuration;
+
+import javax.validation.constraints.NotNull;
+
+public class AccountsDynamoDbConfiguration extends DynamoDbConfiguration {
+
+  @NotNull
+  private String phoneNumberTableName;
+
+  public String getPhoneNumberTableName() {
+    return phoneNumberTableName;
+  }
+}

service/src/main/java/org/whispersystems/textsecuregcm/configuration/dynamic/DynamicAccountsDynamoDbMigrationConfiguration.java

@@ -0,0 +1,48 @@
+package org.whispersystems.textsecuregcm.configuration.dynamic;
+
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.google.common.annotations.VisibleForTesting;
+
+public class DynamicAccountsDynamoDbMigrationConfiguration {
+
+  @JsonProperty
+  boolean backgroundMigrationEnabled;
+
+  @JsonProperty
+  boolean deleteEnabled;
+
+  @JsonProperty
+  boolean writeEnabled;
+
+  @JsonProperty
+  boolean readEnabled;
+
+  public boolean isBackgroundMigrationEnabled() {
+    return backgroundMigrationEnabled;
+  }
+
+  public void setDeleteEnabled(boolean deleteEnabled) {
+    this.deleteEnabled = deleteEnabled;
+  }
+
+  public boolean isDeleteEnabled() {
+    return deleteEnabled;
+  }
+
+  public void setWriteEnabled(boolean writeEnabled) {
+    this.writeEnabled = writeEnabled;
+  }
+
+  public boolean isWriteEnabled() {
+    return writeEnabled;
+  }
+
+  @VisibleForTesting
+  public void setReadEnabled(boolean readEnabled) {
+    this.readEnabled = readEnabled;
+  }
+
+  public boolean isReadEnabled() {
+    return readEnabled;
+  }
+}

service/src/main/java/org/whispersystems/textsecuregcm/configuration/dynamic/DynamicConfiguration.java

@@ -44,6 +44,9 @@ public class DynamicConfiguration {
   @JsonProperty
   private DynamicSignupCaptchaConfiguration signupCaptcha = new DynamicSignupCaptchaConfiguration();
 
+  @JsonProperty
+  private DynamicAccountsDynamoDbMigrationConfiguration accountsDynamoDbMigration = new DynamicAccountsDynamoDbMigrationConfiguration();
+
   public Optional<DynamicExperimentEnrollmentConfiguration> getExperimentEnrollmentConfiguration(
       final String experimentName) {
     return Optional.ofNullable(experiments.get(experimentName));
@@ -86,4 +89,8 @@ public class DynamicConfiguration {
   public DynamicSignupCaptchaConfiguration getSignupCaptchaConfiguration() {
     return signupCaptcha;
   }
+
+  public DynamicAccountsDynamoDbMigrationConfiguration getAccountsDynamoDbMigrationConfiguration() {
+    return accountsDynamoDbMigration;
+  }
 }