Restrict permissions for github actions workflows

Author: mashalifshin

.github/workflows/cross_browser_e2e_test.yml

@@ -1,4 +1,7 @@
 name: cross browser e2e test
+permissions:
+  contents: read
+  pull-requests: write
 on:
   push:
     branches: [ main ]

.github/workflows/lint_and_unit_test.yml

@@ -1,4 +1,7 @@
 name: lint and unit test
+permissions:
+  contents: read
+  pull-requests: write
 on:
   push:
 jobs:

.github/workflows/validate_build.yml

@@ -1,4 +1,7 @@
 name: validate build
+permissions:
+  contents: read
+  pull-requests: write
 on:
   push:
     branches: [ main ]