Update certificate-installation.md (#17)

Add script and instructions for installing the CA certificate on the emulator

Author: pr4bh4sh

docs/certificate-installation.md

@@ -1,4 +1,43 @@
-## Installing CA vertificate on android device
+# Installing CA certificate on Android device and emulator
+
+  
+## Android emulator (only Android 13 and below)
+
+On the emulator, you can use the below command to install the certificate. You must have `openssl` installed and available on the terminal.
+
+1. Start the emulator with the below command
+   ```shell
+   emulator -avd <adv_name> -writable-system -wipe-data
+   ```
+2. Run below commands to download and install the certificate
+    ```shell
+    # This script does not work on Android 14 and real devices
+    curl -o $PWD/ca.pem https://raw.githubusercontent.com/AppiumTestDistribution/appium-interceptor-plugin/master/certificate/certs/ca.pem
+    file=$PWD/ca.pem
+    filename=$(openssl x509 -noout -subject_hash_old -in $file)
+    openssl x509 -in $file > $filename.0
+    openssl x509 -in $file  -text -fingerprint -noout >> $filename.0
+    adb root
+    adb remount
+    adb reboot
+    adb wait-for-device shell 'while [[ -z $(getprop sys.boot_completed) ]]; do sleep 1; done;'
+    adb root
+    adb remount
+    adb push $filename.0 /system/etc/security/cacerts
+    adb remount
+    ```
+
+3. Open `Settings` > `Security settings`> `Encryption and Credentials` > `Encryption and Credentials`.
+
+4. Ensure the installed certificate is displayed under the `System` section of the `Trusted Credentials` settings.
+   
+   <img width="930" alt="image" src="https://github.com/AppiumTestDistribution/appium-interceptor-plugin/assets/6311526/51885560-be30-455e-9b42-2a829a8f5b8a">
+
+**NOTE:** If you save the emulator snapshot you don't need to add `-writable-system -wipe-data` when you start the emulator from the snapshot. `-writable-system -wipe-data` is required only once.
+    
+
+    
+## Android real device and Android 14 emulator
 
 1. Download the `ca.pem` file from [here](../certificate/certs/ca.pem) and save it to the computer.
 
@@ -8,27 +47,32 @@
     adb push downloaded_cert_path/ca.pem /storage/emulated/0/Download
     ```
 
-    The above command will push the certificate to download directory of the android device.
+    The above command will push the certificate to the download directory of the Android device.
 
 3. Open `Settings` > `Security settings` > `Encryption and Credentials` > `Install a certificate` > `CA Certificate` > `Install anyway` and choose the `ca.pem` file and install the certificate.
 
-4. Make sure the installed certificate is displayed under `User` section of `Trusted Credentials` settings.
+4. Ensure the installed certificate is displayed under the `User` section of the `Trusted Credentials` settings.
 
 <img src="./ca_install_steps.gif">
 
+    
+    
+    
+## Verify certificates have been successfully installed
+
 5. Install the plugin by running the command 
 
     ```shell
     appium plugin install --source=npm appium-interceptor
     ```
-6. To Make sure your setup is working connect your android device/emulator to your machine and run the below command
+6. To Make sure your setup is working connect your Android device/emulator to your machine and run the below command
     
     ```shell
     appium plugin run appium-interceptor test-connection
     ```
 
-    A new browser session will be started in the mobile and you should see the below page opened
+    A new browser session will be started on the mobile and you should see the below page opened
      
     <img src="./test-connection.gif">
 
-If you see any errors then retry from step 1 or you can raise an issue with the screeshot and we will guide you with the next steps.
+If you see any errors then please first retry the steps. If it doesn't work please raise an issue with the screenshot and logs and we will investigate it.