MICROBA-253 add phone number field api for coaching plugin (#23406)

* MICROBA-253 add phone number field api for coaching plugin

* Remove hardcoded value

* Requested changes

* Add logger to models_api.py for student
* Import model with underscore to prevent exporting
* Moved return outside of try/catch block

* Add docstring

* whitespace

common/djangoapps/student/models_api.py

@@ -1,6 +1,7 @@
 """
 Provides Python APIs exposed from Student models.
 """
+import logging
 
 from student.models import CourseEnrollment as _CourseEnrollment
 from student.models import ManualEnrollmentAudit as _ManualEnrollmentAudit
@@ -14,6 +15,7 @@ from student.models import (
     ALLOWEDTOENROLL_TO_UNENROLLED as _ALLOWEDTOENROLL_TO_UNENROLLED,
     DEFAULT_TRANSITION_STATE as _DEFAULT_TRANSITION_STATE,
 )
+from student.models import UserProfile as _UserProfile
 
 # This is done so that if these strings change within the app, we can keep exported constants the same
 ENROLLED_TO_ENROLLED = _ENROLLED_TO_ENROLLED
@@ -24,6 +26,7 @@ UNENROLLED_TO_ALLOWEDTOENROLL = _UNENROLLED_TO_ALLOWEDTOENROLL
 ALLOWEDTOENROLL_TO_ENROLLED = _ALLOWEDTOENROLL_TO_ENROLLED
 ALLOWEDTOENROLL_TO_UNENROLLED = _ALLOWEDTOENROLL_TO_UNENROLLED
 DEFAULT_TRANSITION_STATE = _DEFAULT_TRANSITION_STATE
+log = logging.getLogger(__name__)
 
 
 def create_manual_enrollment_audit(
@@ -46,3 +49,16 @@ def create_manual_enrollment_audit(
 
 def get_course_enrollment(user, course_run_key):
     return _CourseEnrollment.get_enrollment(user, course_run_key)
+
+
+def get_phone_number(user_id):
+    """
+    Get a users phone number from the profile, if
+    one exists. Otherwise, return None.
+    """
+    try:
+        student = _UserProfile.objects.get(user_id=user_id)
+    except _UserProfile.DoesNotExist as exception:
+        log.exception(exception)
+        return None
+    return student.phone_number or None