Fix/free space threshold (#760)

* New feature: key retrieval on risk level refresh

* refresh the last time diagnosis keys fetched after transaction call

* TimerHelper update added

* Constants tests

* Formatting

* Fix activity screen orientation.
This solution was proposed by open source contributor: ironjan

* Free space threshold change to 15 Mb

* Updated test

Co-authored-by: Philipp Woessner <philipp.woessner@sap.com>

Corona-Warn-App/src/main/java/de/rki/coronawarnapp/storage/FileStorageConstants.kt

@@ -10,9 +10,8 @@ object FileStorageConstants {
     /** Days to keep data in internal storage */
     const val DAYS_TO_KEEP: Long = 14
 
-    /** Size (Mb) threshold for free space check
-     * TODO Align regarding available space threshold */
-    const val FREE_SPACE_THRESHOLD = 200
+    /** Size (Mb) threshold for free space check */
+    const val FREE_SPACE_THRESHOLD = 15
 
     /** Key export directory name in internal storage */
     const val KEY_EXPORT_DIRECTORY_NAME = "key-export"

Corona-Warn-App/src/test/java/de/rki/coronawarnapp/storage/FileStorageConstantsTest.kt

@@ -8,7 +8,7 @@ class FileStorageConstantsTest {
     @Test
     fun allFileStorageConstants() {
         Assert.assertEquals(FileStorageConstants.DAYS_TO_KEEP, 14)
-        Assert.assertEquals(FileStorageConstants.FREE_SPACE_THRESHOLD, 200)
+        Assert.assertEquals(FileStorageConstants.FREE_SPACE_THRESHOLD, 15)
         Assert.assertEquals(FileStorageConstants.KEY_EXPORT_DIRECTORY_NAME, "key-export")
     }
 }