Fix test_hotspot_upstream_wifi not running consistently

The isStaApConcurrencySupported() returns Unit instead of a
boolean value, which is interpreted as a falsy value when called
from the host in Python. This will cause the Wi-Fi AP + STA
concurrency check to always be skipped and preventing the
test_hotspot_upstream_wifi test from running. This incorrect
logic should be fixed to ensure it accurately reflects the
device's capabilities.

Test: atest CtsConnectivityMultiDevicesTestCases
Change-Id: I4cde38eff43e254450c53d5d3e3aac4027b80e0d
diff --git a/tests/cts/multidevices/snippet/ConnectivityMultiDevicesSnippet.kt b/tests/cts/multidevices/snippet/ConnectivityMultiDevicesSnippet.kt
index c883b78..258648f 100644
--- a/tests/cts/multidevices/snippet/ConnectivityMultiDevicesSnippet.kt
+++ b/tests/cts/multidevices/snippet/ConnectivityMultiDevicesSnippet.kt
@@ -64,9 +64,7 @@
     fun hasTelephonyFeature() = pm.hasSystemFeature(FEATURE_TELEPHONY)
 
     @Rpc(description = "Check whether the device supporters AP + STA concurrency.")
-    fun isStaApConcurrencySupported() {
-        wifiManager.isStaApConcurrencySupported()
-    }
+    fun isStaApConcurrencySupported() = wifiManager.isStaApConcurrencySupported()
 
     @Rpc(description = "Request cellular connection and ensure it is the default network.")
     fun requestCellularAndEnsureDefault() {