Update README.md to include support for Android Emulator (#29)

Author: psiddh

dl3/android/DeepLabV3Demo/README.md

@@ -9,12 +9,16 @@ This guide explains how to setup ExecuTorch for Android using a demo app. The ap
 ## Step 1: Export the model
 Run the script in `dl3/python/export.py` to export the model.
 
-## Step 2: Push the model to the phone
-The app loads a hardcoded model path (`/data/local/tmp/dl3_xnnpack_fp32.pte`) on the phone.
-Run the following adb command to push the model.
-```
-adb push dl3_xnnpack_fp32.pte /data/local/tmp/dl3_xnnpack_fp32.pte
-```
+## Step 2: Set up your device or emulator
+You can run the app on either a physical device or an emulator. To set up your device or emulator, follow these steps:
+
+### Using a Physical Device
+* Connect your device to your computer via USB.
+* Enable USB debugging on your device.
+
+### Using an Emulator
+* Open Android Studio and create a new virtual device.
+* Start the emulator by clicking the "Play" button next to the device name.
 
 ## Step 3: Build, install, and run the app on your phone
 ### On your terminal
@@ -26,9 +30,16 @@ adb shell am start -W -S -n org.pytorch.executorchexamples.dl3/.MainActivity
 
 ### On Android Studio
 Open Android Studio and open the project path `dl3/android/DeepLanV3Demo`. Wait for gradle sync to complete.
-Then simply press "Run app" button (Control + r).
+Then simply press "Run app" button (Control + r) to run the app either on physical device / emulator.
+
+## Step 4: Push the model to the phone or emulator
+The app loads a hardcoded model path (`/data/local/tmp/dl3_xnnpack_fp32.pte`) on the phone.
+Run the following adb command to push the model.
+```
+adb push dl3_xnnpack_fp32.pte /data/local/tmp/dl3_xnnpack_fp32.pte
+```
 
-## Step 4: Run unit test
+## Step 5: Run unit test
 ### On your terminal
 ```
 ./gradlew connectedAndroidTest