Revert "Add one-stop-shop for built-in AEC toggling in APM"

This reverts commit 771b50ca0b92477ce8aabba025e959790dd1a949.

Reason for revert: Introduces error-prone config.

Original change's description:
> Add one-stop-shop for built-in AEC toggling in APM
> 
> This does not change what AEC functionality is available.
> However, a client that only uses this interface - and not the submodule
> pointer accessors - gets simpler code, and is guaranteed not to run any
> two AECs in tandem.
> 
> The submodule interface EchoControlMobile is being deprecated in
> https://webrtc-review.googlesource.com/c/src/+/89392
> 
> Bug: webrtc:9535
> Change-Id: Id9326074e566be6d8768010fc421c457beff402c
> Reviewed-on: https://webrtc-review.googlesource.com/89386
> Commit-Queue: Sam Zackrisson <saza@webrtc.org>
> Reviewed-by: Per Ã…hgren <peah@webrtc.org>
> Cr-Commit-Position: refs/heads/master@{#24066}

TBR=saza@webrtc.org,peah@webrtc.org

Change-Id: I43283a1b22538a4caa77313499989146b2ce67f1
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: webrtc:9535
Reviewed-on: https://webrtc-review.googlesource.com/90060
Reviewed-by: Sam Zackrisson <saza@webrtc.org>
Commit-Queue: Sam Zackrisson <saza@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#24067}
diff --git a/modules/audio_processing/audio_processing_unittest.cc b/modules/audio_processing/audio_processing_unittest.cc
index 3b7c930..4b244fc 100644
--- a/modules/audio_processing/audio_processing_unittest.cc
+++ b/modules/audio_processing/audio_processing_unittest.cc
@@ -176,24 +176,23 @@
 }
 
 void EnableAllAPComponents(AudioProcessing* ap) {
-  AudioProcessing::Config apm_config;
 #if defined(WEBRTC_AUDIOPROC_FIXED_PROFILE)
-  apm_config.echo_cancellation.enabled = true;
-  apm_config.echo_cancellation.mobile_mode = true;
+  EXPECT_NOERR(ap->echo_control_mobile()->Enable(true));
 
   EXPECT_NOERR(ap->gain_control()->set_mode(GainControl::kAdaptiveDigital));
   EXPECT_NOERR(ap->gain_control()->Enable(true));
 #elif defined(WEBRTC_AUDIOPROC_FLOAT_PROFILE)
-  apm_config.echo_cancellation.enabled = true;
-  apm_config.echo_cancellation.mobile_mode = false;
   EXPECT_NOERR(ap->echo_cancellation()->enable_drift_compensation(true));
   EXPECT_NOERR(ap->echo_cancellation()->enable_metrics(true));
   EXPECT_NOERR(ap->echo_cancellation()->enable_delay_logging(true));
+  EXPECT_NOERR(ap->echo_cancellation()->Enable(true));
 
   EXPECT_NOERR(ap->gain_control()->set_mode(GainControl::kAdaptiveAnalog));
   EXPECT_NOERR(ap->gain_control()->set_analog_level_limits(0, 255));
   EXPECT_NOERR(ap->gain_control()->Enable(true));
 #endif
+
+  AudioProcessing::Config apm_config;
   apm_config.high_pass_filter.enabled = true;
   ap->ApplyConfig(apm_config);