PolyGerrit: Simplify some regular expressions

"{}" characters don't need to be escaped.

Non capturing group: (?:P|p) can be expressed as character class: [Pp]
and doesn't involve backtracking.

Change-Id: I20b4f935d2ec868fe7680547b5c7956e74dcc8ff
diff --git a/polygerrit-ui/app/elements/change-list/gr-dashboard-view/gr-dashboard-view.ts b/polygerrit-ui/app/elements/change-list/gr-dashboard-view/gr-dashboard-view.ts
index 9240905..816c8ef 100644
--- a/polygerrit-ui/app/elements/change-list/gr-dashboard-view/gr-dashboard-view.ts
+++ b/polygerrit-ui/app/elements/change-list/gr-dashboard-view/gr-dashboard-view.ts
@@ -58,7 +58,7 @@
 import {firePageError, fireTitleChange} from '../../../utils/event-util';
 import {GerritView} from '../../../services/router/router-model';
 
-const PROJECT_PLACEHOLDER_PATTERN = /\$\{project\}/g;
+const PROJECT_PLACEHOLDER_PATTERN = /\${project}/g;
 const RELOAD_DASHBOARD_INTERVAL_MS = 10 * 1000;
 
 export interface GrDashboardView {
diff --git a/polygerrit-ui/app/elements/change/gr-message/gr-message.ts b/polygerrit-ui/app/elements/change/gr-message/gr-message.ts
index ce17b1e..f913459 100644
--- a/polygerrit-ui/app/elements/change/gr-message/gr-message.ts
+++ b/polygerrit-ui/app/elements/change/gr-message/gr-message.ts
@@ -54,7 +54,7 @@
 } from '../../../utils/patch-set-util';
 import {isServiceUser} from '../../../utils/account-util';
 
-const PATCH_SET_PREFIX_PATTERN = /^(?:Uploaded\s*)?(?:P|p)atch (?:S|s)et \d+:\s*(.*)/;
+const PATCH_SET_PREFIX_PATTERN = /^(?:Uploaded\s*)?[Pp]atch [Ss]et \d+:\s*(.*)/;
 const LABEL_TITLE_SCORE_PATTERN = /^(-?)([A-Za-z0-9-]+?)([+-]\d+)?[.]?$/;
 const UPLOADED_NEW_PATCHSET_PATTERN = /Uploaded patch set (\d+)./;
 const MERGED_PATCHSET_PATTERN = /(\d+) is the latest approved patch-set/;