ci: add keystore/key.properties to repo, fix NDK version, remove duplicate build.gradle

windows/.gitignore

@@ -1,17 +1,17 @@
-flutter/ephemeral/
-
-# Visual Studio user-specific files.
-*.suo
-*.user
-*.userosscache
-*.sln.docstates
-
-# Visual Studio build-related files.
-x64/
-x86/
-
-# Visual Studio cache files
-# files ending in .cache can be ignored
-*.[Cc]ache
-# but keep track of directories ending in .cache
-!*.[Cc]ache/
+flutter/ephemeral/
+
+# Visual Studio user-specific files.
+*.suo
+*.user
+*.userosscache
+*.sln.docstates
+
+# Visual Studio build-related files.
+x64/
+x86/
+
+# Visual Studio cache files
+# files ending in .cache can be ignored
+*.[Cc]ache
+# but keep track of directories ending in .cache
+!*.[Cc]ache/