Carry the Android checkout's uncommitted work into the repo

Four changes lived only in the standalone Android checkout, which is about to
be removed: the foojay toolchain resolver in settings.gradle.kts, an F-Droid
recipe pinned to a commit rather than the v1.1.0 tag, the Gradle daemon JVM
criteria, and the Play Store launcher icon. None of them existed here.

Note that the F-Droid recipe still builds from Calendarr-Android.git, so that
remote has to keep working even though its local checkout is going away.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

android/settings.gradle.kts

@@ -5,6 +5,9 @@ pluginManagement {
         mavenCentral()
     }
 }
+plugins {
+    id("org.gradle.toolchains.foojay-resolver-convention") version "0.10.0"
+}
 
 dependencyResolutionManagement {
     repositories {