Add a flag to enable errors metrics in content profiles

Bug: 317002318
Bug: 294797589
Bug: 315241296
Test: m -j;
Change-Id: I638c8095538c5e785bed615aec8c1859ca4f32d5

flags/content_profiles.aconfig

+package: "com.android.bluetooth.flags"
+
+flag {
+    name: "content_profiles_errors_metrics"
+    namespace: "bluetooth"
+    description: "Enable logging error metrics in content profiles"
+    bug: "317002318"
+}