[mob][photos] Fix build failing in release workflow (#1497)

## Description

Build was failing with this error
```
FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':connectivity_plus:compileReleaseJavaWithJavac'.
> error: invalid source release: 17
```

## Tests

- [x] Ran workflow to verify it's completing.

.github/workflows/mobile-internal-release.yml

@@ -20,6 +20,11 @@ jobs:
               with:
                   submodules: recursive
 
+            - name: Setup JDK 17
+              uses: actions/setup-java@v1
+              with:
+                  java-version: 17
+
             - name: Install Flutter ${{ env.FLUTTER_VERSION  }}
               uses: subosito/flutter-action@v2
               with:

.github/workflows/mobile-release.yml

@@ -9,7 +9,7 @@ on:
             - "photos-v*"
 
 env:
-    FLUTTER_VERSION: "3.19.5"
+    FLUTTER_VERSION: "3.19.3"
 
 jobs:
     build:
@@ -25,6 +25,11 @@ jobs:
               with:
                   submodules: recursive
 
+            - name: Setup JDK 17
+              uses: actions/setup-java@v1
+              with:
+                  java-version: 17
+
             - name: Install Flutter ${{ env.FLUTTER_VERSION  }}
               uses: subosito/flutter-action@v2
               with:

mobile/README.md

@@ -46,7 +46,7 @@ You can alternatively install the build from PlayStore or F-Droid.
 
 ## 🧑‍💻 Building from source
 
-1. [Install Flutter v3.19.5](https://flutter.dev/docs/get-started/install).
+1. [Install Flutter v3.19.3](https://flutter.dev/docs/get-started/install).
 
 2. Pull in all submodules with `git submodule update --init --recursive`