Update test configuration to allow old API level devices

- Add `allowOldApiLevelDevices` flag to gradle.properties
- Clarify comment in tests.yml for API level 24

Author: rfc2822

.github/workflows/tests.yml

@@ -58,7 +58,7 @@ jobs:
     strategy:
       matrix:
         api-level:
-          - 24  # Android 7 (minSdk level)
+          - 24  # Android 7 (minSdk level; see allowOldApiLevelDevices in gradle.properties)
           - 30  # Android 11
           - 32  # Android 12L
           - 37  # Android 17

gradle.properties

@@ -12,4 +12,8 @@ org.gradle.caching=true
 # Android
 android.useAndroidX=true
 # Dokka
-org.jetbrains.dokka.experimental.gradle.pluginMode=V2Enabled
+org.jetbrains.dokka.experimental.gradle.pluginMode=V2Enabled
+
+# Automated tests with gradle-managed devices require SDK level 26 by default.
+# Can be removed as soon as minSdk is 26.
+android.experimental.testOptions.managedDevices.allowOldApiLevelDevices=true