Added: Init TermuxShellEnvironment at app startup

This will currently cache `TermuxAppShellEnvironment` so that its not regenerated for each shell started since it contains some slightly expensive operations.

app/src/main/java/com/termux/app/TermuxApplication.java

@@ -60,6 +60,9 @@ public class TermuxApplication extends Application {
             }
 
             TermuxAmSocketServer.setupTermuxAmSocketServer(context);
+
+        // Init TermuxShellEnvironment constants and caches after everything has been setup including termux-am-socket server
+        TermuxShellEnvironment.init(this);
         }
     }
 

termux-shared/src/main/java/com/termux/shared/termux/shell/command/environment/TermuxShellEnvironment.java

@@ -28,6 +28,11 @@ public class TermuxShellEnvironment extends AndroidShellEnvironment {
         shellCommandShellEnvironment = new TermuxShellCommandShellEnvironment();
     }
 
+    /** Init {@link TermuxShellEnvironment} constants and caches. */
+    public synchronized static void init(@NonNull Context currentPackageContext) {
+        TermuxAppShellEnvironment.setTermuxAppEnvironment(currentPackageContext);
+    }
+
     /** Get shell environment for Termux. */
     @NonNull
     @Override