Fix file import/export on debug builds

Debug builds added .debug to the actual applicationId, but the settings XML
used a flavor-level applicationId resource without that suffix, causing an
"Unable to find explicit activity class" exception. Solved by generating the
applicationId resource from each resolved variant and keeping debug and
nightly branding limited to the launcher label. Also added an Android test that
verifies the settings targets resolve on-device.

build.gradle

@@ -107,7 +107,6 @@ android {
         nightly {
             dimension 'version'
             applicationId 'de.dennisguse.opentracks.nightly'
-            resValue 'string', 'applicationId', 'de.dennisguse.opentracks.nightly'
 
             versionCode getVersionCodeNightly()
             versionName getVersionName()
@@ -119,7 +118,6 @@ android {
             // Non-reproducible: https://f-droid.org/de/packages/de.dennisguse.opentracks/
             dimension 'version'
             applicationId 'de.dennisguse.opentracks'
-            resValue 'string', 'applicationId', 'de.dennisguse.opentracks'
             versionNameSuffix 'irreproducible'
         }
         reproducible {
@@ -128,7 +126,6 @@ android {
             // PlayStore: https://play.google.com/store/apps/details?id=de.dennisguse.opentracks.playstore
             dimension 'version'
             applicationId 'de.dennisguse.opentracks.playstore'
-            resValue 'string', 'applicationId', 'de.dennisguse.opentracks.playstore'
 
             base.archivesName = "de.dennisguse.opentracks.playstore_${getVersionName()}_${android.defaultConfig.versionCode}"
 
@@ -169,3 +166,12 @@ dependencies {
 
     androidTestUtil 'androidx.test:orchestrator:1.6.1'
 }
+
+androidComponents {
+    onVariants(selector().all()) { variant ->
+        variant.resValues.put(
+                new com.android.build.api.variant.impl.ResValueKeyImpl("string", "applicationId"),
+                new com.android.build.api.variant.ResValue(variant.applicationId.get(), null)
+        )
+    }
+}