Created biometric provider.

Test: Manually verified data was fetched successfully.
Test: adb shell device_config put biometrics_framework
com.android.settings.flags.biometric_settings_provider true
Test: atest BiometricSettingsProviderTest
Bug: 303595205

Change-Id: I154754eed7c36d659853ed83cc18a2e446fb7678

aconfig/settings_biometrics_framework_flag_declarations.aconfig

@@ -0,0 +1,8 @@
+package: "com.android.settings.flags"
+
+flag {
+  name: "biometric_settings_provider"
+  namespace: "biometrics_framework"
+  description: "This flag enables or disables the BiometricSettingsProvider"
+  bug: "303595205"
+}