termux-api: Ensure /system/bin/am_process in PATH

Closes https://github.com/termux/termux-api/issues/12

packages/termux-api/build.sh

@@ -1,6 +1,6 @@
 TERMUX_PKG_HOMEPAGE=http://termux.com/add-ons/api/
 TERMUX_PKG_DESCRIPTION="Termux API commands"
-TERMUX_PKG_VERSION=0.12
+TERMUX_PKG_VERSION=0.13
 
 termux_step_make_install () {
         mkdir -p $TERMUX_PREFIX/bin

packages/termux-api/termux-api.c

@@ -35,6 +35,8 @@ void exec_am_broadcast(int argc, char** argv, char* input_address_string, char*
         char const* const file = "/system/bin/am";
         // Avoid the system am binary from linking to wrong libraries:
         unsetenv("LD_LIBRARY_PATH");
+	// Ensure /system/bin/app_process is in path, which is needed by am in some systems:
+	putenv("PATH=/system/bin");
 
 	// The user is calculated from the uid in android.os.UserHandle#getUserId(int uid) as "uid / 100000", so we do the same:
 	uid_t current_uid = getuid();