fix(ooniprobe): use ooniprobe-cli-unattended for unattended runs (#714)

This diff changes the software name used by unattended runs for which
we did not override the default software name (`ooniprobe-cli`).

It will become `ooniprobe-cli-unattended`. This software name is in line
with the one we use for Android, iOS, and desktop unattended runs.

While working in this diff, I introduced string constants for the run
types and a string constant for the default software name.

See https://github.com/ooni/probe/issues/2081.

pkg/oonimkall/session.go

@@ -364,9 +364,9 @@ type CheckInConfig struct {
 	// Platform is the mobile platform (e.g. "android")
 	Platform string
 
-	// RunType indicates whether this is an automated ("timed") run
+	// RunType indicates whether this is an automated (model.RunTypeTimed) run
 	// or otherwise a manual run initiated by the user.
-	RunType string
+	RunType model.RunType
 
 	// SoftwareName is the name of the application.
 	SoftwareName string

pkg/oonimkall/session_integration_test.go

@@ -259,7 +259,7 @@ func TestCheckInSuccess(t *testing.T) {
 		Charging:        true,
 		OnWiFi:          true,
 		Platform:        "android",
-		RunType:         "timed",
+		RunType:         model.RunTypeTimed,
 		SoftwareName:    "ooniprobe-android",
 		SoftwareVersion: "2.7.1",
 		WebConnectivity: &oonimkall.CheckInConfigWebConnectivity{},
@@ -307,7 +307,7 @@ func TestCheckInLookupLocationFailure(t *testing.T) {
 		Charging:        true,
 		OnWiFi:          true,
 		Platform:        "android",
-		RunType:         "timed",
+		RunType:         model.RunTypeTimed,
 		SoftwareName:    "ooniprobe-android",
 		SoftwareVersion: "2.7.1",
 		WebConnectivity: &oonimkall.CheckInConfigWebConnectivity{},
@@ -337,7 +337,7 @@ func TestCheckInNewProbeServicesFailure(t *testing.T) {
 		Charging:        true,
 		OnWiFi:          true,
 		Platform:        "android",
-		RunType:         "timed",
+		RunType:         model.RunTypeTimed,
 		SoftwareName:    "ooniprobe-android",
 		SoftwareVersion: "2.7.1",
 		WebConnectivity: &oonimkall.CheckInConfigWebConnectivity{},
@@ -366,7 +366,7 @@ func TestCheckInCheckInFailure(t *testing.T) {
 		Charging:        true,
 		OnWiFi:          true,
 		Platform:        "android",
-		RunType:         "timed",
+		RunType:         model.RunTypeTimed,
 		SoftwareName:    "ooniprobe-android",
 		SoftwareVersion: "2.7.1",
 		WebConnectivity: &oonimkall.CheckInConfigWebConnectivity{},
@@ -392,7 +392,7 @@ func TestCheckInNoParams(t *testing.T) {
 		Charging:        true,
 		OnWiFi:          true,
 		Platform:        "android",
-		RunType:         "timed",
+		RunType:         model.RunTypeTimed,
 		SoftwareName:    "ooniprobe-android",
 		SoftwareVersion: "2.7.1",
 	}